Your motor is very close to my build. I'm running a roller cam with 240 degrees of duration, OOTB Eddie heads and 10.5:1 compression. It did have a 770 Holley on it for the first year and I just swapped over to a Sniper EFI.

That thing is going to develop a crap ton of torque. Whatever converter you decide on, make sure it's a tight one - you don't need a lose converter with a motor like that. A tight converter will make part throttle cruising and throttle response much more enjoyable.

The one I'm running now is a Turbo Action 17809ST. It's specifically made for transmissions that have lockup input shafts, but it doesn't have the lockup internals in it.

Give Turbo Action a call, you won't be disappointed.