4S1P VS 4S2P lipos?

The pack you're looking at is 5000mAh and 25c. 5000*25=125,000. 125,000mA is 125 amps. So you are looking at a pack with 125A continuous discharge, ADVERTISED. Unfortunately we can't really look at the manufacturers ratings as 100% accurate.

TP's are nice and all, but you might look at some trakpower, neu energy, polyquest. There are a few others in that price range that might do a bit better than the thunderpower, although TP makes some excellent packs too.

J>