2600 Kv rated motors? which one?

If you're assuming that the lower KV motor always has more torque, you'd be wrong. Without looking over all the specs, i'd assume that the mega has more torque. They're pretty friggin massive. Of course, I havn't looked at them both that closely so I can't say, but it's worth further investigation.

One thing I can darn well gaurantee, is that mega is NOTHING like your vxl, 5mm shaft or not.

J.