I would have to agree with Gacjr0, you have the BEST system out there. As for the lipos, MOST people I know who run brushless have lipo. but then it gets into battery care, do you wonna cycle batteries every now and then? Do you take them down at the end of the day and put alittle bit of charge back in them for the next week? if you do that and dont mind doing it, stick with IB, EP, 4200's. if you are getting tired of doing it go lipo!.
Hope this helps,