which lipos to get?

[MetalMan]

Heh, you're not too far from me. I'm about 5mins from SoCal RC Raceway.
The 4000mah should be fine, since it's rated at 60amps continuous. I have the older style Maxamps 2s 6000mah (10C/60amps continuous) and am using that in my Dark Impact (1/10 4wd buggy) with a Mamba Max 5700 system, which requires more power than the SS5800 in a 2wd buggy.

BTW, if you're familiar with the Hobby People in Fountain Valley, that's where I work :). Do you know Geovanni by any chance?