Feel free to contact me when you are ready...most of the time I can only do this for 8 people a year (including any I want for myself) but I seldom use all of them so it's likely I could still get you a VPP claim number when you are ready to buy.
There are tons of different price ranges, espeially for wheels. I sell wheels that range in price from $400 to $1700 per wheel and everything in between. As for tires, you are looking probably in the mid $400 range for each rear and low $300 range for each front. What budget do you think you would be working with for wheels & tires?
No, those 18s were from my time attack 350Z. I just put them on the 370Z to see if they fit. I still have the stock 19s on my 370Z. The 315s did not need spacers though to answer your question.