How much lower...
 

...are the 2003 Blobeye Sti's and WRX's than the GX sport?

I have just bought a GX which is half way to being full replica. Not sure whether to get full suspension upgrade, or save few pennys and initially get lowering springs. Currently have white 17s on, but also considering uprating to 18s if thats is going to affect suspension?

eBay???

Not at all, Subaru quoted the same ground clearence for them all, although from memory the WRX's actually sit a little lower at the front due to the heavier engine.

Simon