Ok, I'll pick a kit and start on it. 

As to parts I've been buying them for over a year now.  So far, I've got the following:  Battery, radio receiver (I'm going to share a radio on this one),  Tamiya battle system, Impact rear idler wheel assy, wheel bearings, sleep and mute relays, charging port, on/off/charge switch, the Nick A. parts (gun, trans cover, and hatch), and a bunch of Bob Morey metal detail parts such as the pintle hitch etc (I bought a bunch of his stuff some time back, and am unsure of what all I have )..  I'm not adding any item that isn't in the kit though.  I might go for metal tracks, but later, if at all.  I'm not real pleased with my last set of Impacts that had all the bent guide horns (Panther).   I'm probably going to get DT's transmission brace,  but am unsure right now.

Still on the fence regarding the oil reseviours, haven't decided.  I generally like to replace all the small breakable parts out before they break, but this one I'm trying to keep simple.  I'm going to install the stock Tam transmissions, as my last Impact set (on the KT) had a bent drive shaft (still works ok, but had to remove the donut hull bearing to make it work).  I should have given that KT the number 666 instead of 332.  My firing problem (sound cuts out sometimes on recoil) turned out to be a bad MF-01.  I'll be sending that in for repairs too.  So, its down for 9 more weeks.  10 battles per year takes a toll on them.