what do you think the biggest rims i could use in a 2001 golf. its not lowered now but it is a possibility in the future. i was thinking around 17"... would that cause me any problems?

The biggest you can put on w/ lowering 2" is 18x8.5 in the rear and 18x8 in the front. ANy bigger and it will need to have fenders rolled. you can put on 19's with no drop and have no issues