I have a built 7 bolt 2.4 as well. All new stock parts were used except eagle rods and ross pistons. I'm pushing 7000 miles and at least 8 trips down the quarter mile. I would NOT recommend building a 7 bolt. I started building mine over 2 years ago when people were still hoping the 2.4 was less prone to crankwalk. It's since been proved that it's probably just as bad as the 2.0 as far as your chances of crankwalk go. I wanted to do the 7 bolt because it's less work to install in a 2G, but the paranoia of having a 7-bolt at this point was/is not worth it. Why risk it?
If you do build a 7-bolt consider doing what this guy did:
http://www.dsmtuners.com/forums/showthread.php?t=8817
Creating dowel pins sounds like a really good idea.
When you're done I'd go with a twin-plate clutch to be safe. I'm running the HKS and the pedal pressure is like stock but it's really chattery.