Not too many years back, I was in the same boat as you. The difference is that I've actually worked in the US, and had current ASE Master and L1 certs (Exp last Dec...)
First thing I'm going to suggest is to head over to iATN, and do some reading in the Shop Management and Industry Issues forums. If you're a member, you can search the archives. There're miles of pro/con threads discussing flat-rate, dealer vs. independent, and on and on.
I actually flew to the US several times, and interviewed at quite a few places, talked to quite a few people, and did an unbelievable amount of research on the entire what's what. The following is my opinion, and paints with a broad brush, but still paints a pretty accurate picture for someone looking from the outside-in.
Matthew R. wrote on May 13
th, 2015 at 1:09am:
1)Should I start of at the dealership or an independent garage?
Indy. Of course there are good dealers, but most of the places just use and chew up techs. Flat rate, and over staffed, so it's tech vs. tech. Remembering the broad brush I talked about, most people who have left the dealer, and now work indy, do not miss the dealer. They miss factory tooling if the indy doesn't use it, but overall, they don't have much nice to say about it. Of all the places I interviewed, the dealers were all a joke. One Toyota offered $20 per hour starting, but was mostly maintenance, and looked over-staffed. One Chevy (same company) offered $27, but was mostly warranty, and overstaffed Meaning you're getting $27 per hour for the 3 hours of work you can scrounge). You can read about this particular set of problems on iATN. Either way was a joke, as I can almost always crush "book time" and they're wanting to pay less than 25% of the door rate, and for work they don't have? LOL.
I interviewed with a few indies which were just advertising, and was highly disappointed. Then I narrowed that down to places that looked like they had their stuff together. Specialization, hourly with bonus pay plan, etc. These turned into real interviews vs. just looking to say yes to anyone off the street. Money and benefits blew any dealer, and the crappy indies out of the water. Most of these places want techs with at least an ASE master cert. They take pride in their business, and want their techs to do the same. Stay out of the corporate chain stores.
Matthew R. wrote on May 13
th, 2015 at 1:09am:
2) How is life working flat rate?
Almost everyone hates it in public discussion. It seems to have been good years ago, but now it's used to put losses from bad management on the mechanic. Many of the high-end indy's pay hourly, or have some kind of pay plan with hourly and performance bonus. There are reams written about the ills of flat-rate, while almost no one has anything bad to say about hourly. It's possible you could luck into something good, but it's highly doubtful. At first, I thought that would be a great system, and I could make a fortune! Then I dug. And dug some more... No effing way would I subject myself to that. The worst thing I ever read about hourly, in a FR discussion, was: "I don't make quite as much, but my life is much better."
Matthew R. wrote on May 13
th, 2015 at 1:09am:
3) Can I provide enough for my family in this career?
Sure. Find a good shop with lots of work, and a good pay plan. Remember that the
average pay for a tech in the US is $39K. You will have a big tool expense paid out of that, health insurance will be ridiculous for anything that actually helps you, and on and on. Food is expensive. Taxes are expensive... I was under the assumption that the cost of living in the US would be substantially lower than where I am in Japan. Not in SW Michigan, it's not.
Matthew R. wrote on May 13
th, 2015 at 1:09am:
4) Any other things to consider that I may have overlooked?
Specialize. Find a shop that specializes in something. Like Toyota, Nissan, Honda, for instance. If you work in an "all makes and models" shop, you're not going to like it because they won't be tooled for what you're doing. See what tools they have. How is their work load vs. techs. If they're paying hourly, that shouldn't be an issue, as they're probably hiring because they actually need someone, and not just hiring to fill a four-hour labor hole. Once again, loads of reading about this on iATN. One huge bonus you'll find in a proper shop, is access to real service info! A lot of mechanic that work overseas are shit-hot at fixing cars because they have to be thinkers. We don't have access to factory diagnostic tools, and info. If you were good at finding and fixing problems before, wait until you have access to factory SI, tools, TSB's and so on. If you work in a crappy indy shop with nothing more than an old Snap-on scan tool and Alldata... It still might be better than where you're coming from :-0 At least the info applies to the car you're working on. US techs really don't know how good they have it compared to pretty much the rest of the world.
Matthew R. wrote on May 13
th, 2015 at 1:09am:
5) Should I consider another career instead of continuing being a technician?
Maybe, but remember that most skilled trades will require some kind of license.
In the end, it just wasn't worth it to make the move. I don't know what your situation is in the PI, of course. I suggest taking some time to really get a whiff of that grass on the other side of the fence. I was in the same boat, and I thank my lucky stars that I took the time to check it all out. Turned out I was just tired of the grass on my side. Take a trip, and talk to people, in person and on the boards.
Many of the expat's I know here have a retirement plan that includes settling in the PI

Just do a lot of digging before you jump. It's not for everyone, and the jump back will be twice as painful.
Oh yea, and if you haven't done the paperwork for your wife...get ready for that mess, and be ready to pay, and pay, and it will probably take close to a year. Something I found is that it's easier for me to pick up my whole family and immigrate to Australia or Canada than it is for me to get the visa for my wife, who's been married to an American for 25 years, and has three American children... Go figure

You may need to already have a job before they'll even let her in...