blackdragonauto.com sells a carpet kit of you are still looking for one. I haven't used it, but it's definitely worth checking out.
I agree with the not doing the rb20det
Go for the rb25det or splurge for the rb26dett if you want to dump a lot of money. You can get the rb25det's for a decent price because everyone that is super serious about the power opts for the rb26dett.
I'm sure you've poured over the rb section on hybridz though