I had trouble with VW wheels before. Not all of them are consistant to specs, apparently. Some banged my calipers, some didn't, same set. If you're tight on bucks starting off, go with the 185's. Yes, there is a difference in handling, but not much. Two main differences come with true final drive ratio with the different diameter tires...one is lowered top speed/greater acceleration, and the other is overheated/faster wearing tires. A bunch of that depends on where you race.
If you race on long, high speed courses, you'll be in a bind. Shorter, tighter courses, the 185's will be great.