Blueblaster

There seems to be a lot of discussion about wheel offsets and which wheels will fit which model. I have a MY05 STI and consequently seem to have as many options as a bloke with a new Impreza and not many options . Other than enquiring about every wheel I see on the internet, is there a way of telling which wheels will actually fit the Blueblaster?

I generally try and play things safe and will probably end up with some OZ Superleggeras. Have found some for 256 quid each without tyres. Am I likely to beat this price by much or is it time for a second mortgage.

Thanks muchly