I have be searching on TGO and pro-built.net to see what are the best, and the vigilante came out on top. They have one that was a 9.5" convertor and 12#s lighter than stock. It says that it can lock-up even under full throttle.

I was thinking that anything less than a 10" needed a cooler, is this correct?

This is going to be a daily driver, so I am looking to stall around 220-2600.

 

Yes, you should install a larger cooler for the tranny. 20,000+ GVW cooler should be fine.