new wheels

Just about to order a set of wheels nd need to know a few things from the guys in the know! I've decided to go for 15" as she's going to be slightly lower than normal. the wheels i want are 7.5 x 15" is this going to cause a problem with he arches??

also a i have a choice of tyre sice 195/50/15 or 195/45/15 i know the size relates to height but does it really matter? (saving of 6 per corner if it doesnt lol)

195/45 looks better.

T