Go 06+, 2.5 is torquey. Tons of reputable vendors, lots of support.
Common mod faq's here http://forums.nasioc.com/forums/showthread.php?t=533787
I am going suspension first, then power. Right now I have just a few mods for comfort, and it is a great DD. No problems whatsoever. Trans is a bit notchy, but you've had a T56 so you understand it.