In mid '97 I moved to England and came with my VW Golf (stick, steering wheel on the left side) via ferry from the mainland. I drove with it in England for about 2 years and found it fairly easy
In the US, I wanted to drive stick and I guess the car dealer was really happy to dump his only model on me
Anyway, coming back to the UK last year without any car at all, I rented one; it was the first time ever I had driven a british car with steering wheel on the right hand side!
Terrible! I just couldn't get a feeling for sitting at the right hand side of the car and calculate the distance from my car to the other vehicles to the left. Several times I was close ripping the left outer mirror off with my tight manoevring ... parking was a nightmare too. And then, of course, each time I had to change gear, I banged my right hand at the driver's door in search of the stick ...
If car insurance wasn't so high for foreign cars, I'd rather get me one from anywhere in Europe and drive it over here, I felt it was so much easier. BTW, though I'm not really a fan of automatic cars, I think it would make sense to drive one in London ... peak time stop'n go traffic is a sure death sentence for the engine and gearbox (not to speak of hand cramps and numb foot).
I can really feel for all you who have to learn 2 things at once (stick and left hand traffic)!