Alloy Wheels?

[MR2Shane]

I currently have the original alloys on my MR2 and wanted to replace them with some OZ Superturismo GT's, I wanted to do this without any suspension or arch modifications at the moment but it seems that it's hard to find tyres for the rear being size 225/50/R15 and I don't need new tyres but for when the time comes for replacing tyres, I thought that maybe 16" alloys would be the ideal size? - I don't want to lose any handling or go through extensive work to prevent rubbing.

I understand many have decided to use 17" alloys but it seems to make them look good you need to lower the suspension otherwise the car just seems to high up. The alloys I want are: here

So really, I just wanted the details for a size that I can put straight on without any rubbing problems and offset etc.

Any advice appreciated