[RC-Monster Mike]

Welcome to the forum! I see you have read up on a few items already so you probably know your way around somewhat already. The 9918 controller could probably handle a 6s Lipo set-up, but it would be technically over the rated voltage so any warranties would be voided. I have been working on using a 5s Lipo setup, which will be within the rated voltage of the controller. The motor I was planning on was the xl2400, but the 7xl or 10L would be about the same performance. Now that the heatsink/motor clamp is a reality, I may run the Feigo motor myself (10L for me). You could get yourself 2 sets of 3s 3200s and 2 sets of 2s 3200s (so two sets of 5s 3200s for running). These would run a little over $400. Then, a Lipo charger would run around $130 (I use the astroflight, which can charge at a high amp rate and high cell counts for Lipos). This would get you in under budget (not counting motor and controller) and I am sure you would be extremely happy with the performance. The batteries will fit fine in the g-maxx chassis as well. Also, the UBEC is rated up to 30 cells (so almost 10s lipo), so no problems there, either.