You have very good taste in wheels my friend
However, 'cheap' is a relative term when it comes to these wheels...expect to pay about $3k+ for JUST the wheels in 20" depending on options. From my experience you may wanna check out Ravspec -->
JDM / USDM Auto Performance Parts Wholesale - Specialized in STI, EV0, 350Z - Ravspeconline.com
Dont puss out on the offsets either! You can go very agressive with these wheels. I recommend:
F: 20x9.5 +15 to +20
R: 20x11 +0 to +10 depending on how meaty you want to go in tires.