whats going to break...
well, the stock tranny if not locked in 2nd gear, the rear diffs, the rear toe in rods.
that xelorin motor sucks, the fieago sucks even more and the hobbywing ESC's are a pain to program.
but other than that
man, just go for what you can afford, have a blast with it then upgrade when you finally kill it.
when you upgrade to say a tekin RX8 or a MMM combo you will be wow'd all over again
nearly all of us run turnigy or zippy 30c lipo's, 4s is a minimum usualy.