LiPo upgrade

Hi all,
Having had my NiMh packs die at the UK champs, I am looking to replace them. I have thought about buying another set of the same, but I have a plan to build a spinner at some point soon, and will be requiring some lighter batteries with a higher discharge rate. Seeing as I already have the kit to charge LiPos, I thought it would be the ideal opportunity to upgrade. I have been looking around, and know that many of the people with LiPo experience suggest using Hyperion, Thunder Power or Flight Power batteries, so I have decided to concentrate on those brands. I have found what seems to be a suitable pack, from Hyperion, on the Robot Birds site: http://robotbirds.com/catalog/product_i ... ts_id=1527
Could anyone in the know offer me advice on this pack, and/or suggest better ones if it is unsuitable for the drive in a feather. Considering that a 25A Sabretooth can handle the drive, I would have thought that a battery capable of 64 amps continuous discharge would be fine. I understand all the dangers of LiPo use, and would of course take extra care when using them.
Also, if anyone could suggest a low voltage alarm that takes the form of a light instead of a buzzer, I would love to know.

Wow, long post!
Alex