What cheap high torque servos would you guys recommend? For my first antweight, I'm going to go for something simple - a pushbot with lifting spikes.

So far, for my shopping list I just have:
- Planet 5 trans/rec set
- HDPE

Anything else I need apart from the servos? I have some mini go cart wheels years ago from lego mindstorms somewhere, but I can't remember if they would be the right scale, or give good traction.