The Burst Wizards aren't really suitable Fets. You shouldn't skimp on shims and helical gears are a real pain in the ass to shim. In addition, the SHS HT motor will be torquey enough to pull that spring on 18:1s. The Raptor's are a little fancy for me, but neither of them allow PnP with a PWD Board which is the ultimate fail safe for lipos. For cylinder and piston heads I like ARS products. Lonex is also a very recommended brand if you want to take a look at those.