I really have no idea how much labor costs... my personal opinion has always been that if you don't DIY, you're getting ripped off. But obviously thats a little biased.

The problem with just shooting for just a ~7k redline is that it really doesn't let that vtec head shine. IMO, a plain old b18b is a better motor than a b18c5 from 0-5k rpm... from 5k-7200, you'll be enjoying yourself, but when you shift, you'll drop back down to the pre-changover revs where that head might feel a bit sluggish... Which prompts another question... what transmission are you using? Either B16 or B18c will be ok (i'd personally prefer the shorter gearing of the b16a tranny), but you should avoid the LS tranny.

I dunno... either way, it will definitely be faster than you z6, but I'm just concerned that you wont be satisfied and end up rebuilding it in a year anyway.