The only two issues are:
1. Rotational mass
2. Adapters are at least 15mm thick so you need to take that into account when considering wheel choice
Do you honestly think there aren't enough? 5x112 gives you massive choice from VAG to Merc, BBS and several other aftermarket manufacturers, and you've even got access to jap spec wheels (5x114) and some GM/Vauxhall wheels (5x110) with wobble bolts