Conversions are not cheap, all the ones I've done (Emaxx to FLM Ext Emaxx, G2R, and HB Lightning Pro 1/8th buggy) they all wind up costing far more than what you budget. A brushless setup will find every weak link in your drive train and destroy it so you have a lot of upgrading to do before you get to the point that a conversion is reliable - doesn't break everytime you run it.

I have no experience with LSTs, but their rep is solid. If you have no experience doing a conversion, you may be better off going with the E-Revo since stuff's already available to make it BL. To me, the only choice is the Castle 2200 combo, I've run 3 of them with no probs and looking to do a 4th.

Welcome to the forums, btw.