Just keep an eye out for a keep GC8 seat and knock up one yourself from MDF then paint it and enjoy.
Something similar to this but a bit more stylish haha:
http://gt5mania.com/diy-race-seat/
Here's one that's a little more than what you want but it shows you what's possible when you do it yourself.
http://www.perth-wrx.com/vb/showthre...ghlight=arcade