With stage 1's? get a vb and a larger cooler. Keep the stock pan.
I would not install anything other than BTS. As soon as I get another stock VB, I'll test out John Woods VB. I hear they are very good also.
I gave away a FTVB. Had nothing but issues. I had the trans screaming at me at the rev limiter not wanting to shift using some seriously extreme tunes.
The man who wrote the tunes was in the truck as a witness. I'll let you guess who that is. Now the trans shifts properly under WOT or part throttle with ease.