I bought IP 30C 5000mah lipos from rc mushroom. They were incredibly poorly packed and I was lucky that someone in the Post Office took the time to re-package them - they arrived completly out of the box and I would have gotten an empty box if someone at the PO had not helped out. Not sure I'd buy anything else from them if their packing is that poor.

If you want "really good" lipos, I would look at Enerlands. I've run a data recorder with my IPs and I'm not impressed, they show a lot of voltage drop at high current draws. The 30C rating on mine seem to be optimistic and not realistic based on what I've seen from my data recorder.