It might be worth looking into tyres first matey, have you got good tyres with good tread? To be honest at this time of year there's not much you can do with the wet/cold roads. There's not a lot of traction knocking about at this time of year, especially for turbo #2.
I have turned my boost down now (about 1 bar) as the car is much smoother to drive, and the biggy is the backend stays in line a bit better.
This is your first winter in the car mate, the best advice I can give you is take it very easy. I bought mine this time last year, and got told the same. You'll notice quite a few people crashing/bumping there cars over the next few months.
Anyway if you still want to get some new rims mine are Ultralite 755's/Nur's, I can't remember the exact widths and offsets, but they're 18's. I got them from Paul Whiffin on here (he owns Whifbitz), other than that Gaz Walker from Envy was doing good prices on them too.
I asked Paul for the correct offset to get UK brakes under the fronts (in case I upgrade)