Man, get an E Sledge (or Yak) a Himax 2015 4100, GWS EPS C Gearbox with D gears, a spare GWS D pinion, Castle Creations Phoenix 25, an Electron 6 or Berg 5 RX, some HS-55 or GWS Pico BB servos, and some 3S 1200 or so lipos. That is a proven combo, you won't have to break trail.

The ShockFlyers are OK if it's calm or indoors, but they won't take a licking like the E Sledge, and you really need some small motor/battery to keep 'em light. The larger/tougher E Sledge is more versatile, IMHO.

Just my $.02