Will try and give some idea:
Medical postgraduate training is all changing in the UK just now. In addition, an attempt to increase the number of home-grown doctors (the UK, like the US, has relied on IMGs for years) means that there are huge numbers now competing for postgrad training places. Additionally, all members of the EEA (european economic area) have as much right as UK citizens to apply for postgrad training. Therefore, there is a lot of discussion going just now about how to restrict IMGs fairly from over-competing with Brits/other EEA citizens.
So, firstly, it is hard, and will become much harder for IMGs to work in the UK. You would also have to sit the PLAB exam, and prove English ability.
And surgery, like anywhere else in the west, is hugely competitive anyway.
Hospital consultant salaries are around £110,000 (v. roughly). This can be supplemented with bonuses, clinical excellence awards, etc etc. (Private work: one of our opthalmology lecturers told us she had colleagues who could earn anything between £500,000 and £1 million in the south east in private practice.)
I don't know about the hours. Surgical specialties have afwul on-calls to do. This may be 12 hours on, 24 hours on call, 12 hours on. You could end up working 48 hours straight, but I doubt that that would happen often. And it depends how often you do an on-call - 1 in 3? 1 in 4? How many weekends? This will all vary from surgical specialty to specialty. In short, I don't think it's miles better than the US. From what I hear, Australia seems to have a much more relaxed (better organised?) system, if that's what you're looking for.
Also, our postgrad training is so different from the US. 5/6 yrs med school, two Foundation years, then specalising (7-8 yrs for surgical), plus any MD/PhDs, etc. I think it would be difficult if you had done a three/four year residency to know where to slot you in to the system without you having to repeat some time, get more experience in other areas (we do a lot more wide-ranging experience before specialising than you do - you basically start specialising straight out of med school), etc.
Hope that helps. It's not easy...but nothing's impossible! Arrange electives in the UK. Get in touch with the appropriate Royal College once you've decided which specialty.
Good luck!
