Which Lipo for cat sx. 3600 or 4900

[Colinevan]

I need to buy me a lipo now....

Iv been recommended the trakpower 3600...

However iv now been told that in certain circumstances, that i might be better going for the 4900 as it is better at providing a constant surge of power and maintaining it. Iv heard of stories whereby cells expanding with the strain if used with powerful brushless motors causing more drain.

Now im no expert but as funds are tight i need to get a lipo that needs to be trouble free.

Any advice , or recommendations would be greatly appreciated.

Thanks

Col.