Kman- get a PEQ-15 with a LiPo if you are gonna keep a PEQ box, the 15 looks much better than the 2. Otherwise, I'd go for a new stock, crane or full, and get the gun wired to that.
RenegadeSanta- I've heard very good things about those, the only real downside is that they're feckin' expensive- for the cost of two of those you could have a box of MAG (considered some of the best magazines available) midcaps. That said, they are supposed to feed nicely. Don't get the Star Green label ones, if you want P-Mags, those are the way to go. Also, just saying, they're not full metal, they're polymer (which is the P in P-mag, btw)