i would go with arrma, if even only for the parts support. you can make any rc fast, but how many times will it get there before destroying it after a small mistake/miscalculation. though i know some have had issues with the 4s arrmas, it seems as though it was the early batches that had some hiccups, but knowing how quickly arrma fixes issues with their rigs, (servo saver comes first to mind). then in the end you can eventually upgrade the truck to be faster.
faster car=faster broken parts
arrma broken parts= go to LHS
JLB broken parts= order online and wait for the mail
especially with how popular arrma is upgrades are going to be more and more available through many companies (Hot racing, T-Bone racing, M2C, Voltage, RPM, etc.
JLB makes their own, but no/very little other aftermarket support by other companies.