As mentioned above, you can change the TV pressure values for shift transitions, and that will help dial it in nicely.
I lowered the values under normal driving conditions, so the shift transitions or nice and easy. For heavy throttle conditions, I raised those values so it yields a nice snap for each shift.
I've been running/abusing a Circle D converter for years now and no problems to speak of. It's a multi-disk lockup that is much stronger than stock with a 3000 stall speed (you can get them with a lower stall speed too). Their website doesn't have info for E4OD applications so it'd be best to call them.
Definitely run the valvebody first. Mechanical is always better than a computer for Tranny upgrades. Also a firmer shift is actually better for the longevity of the transmission. Smooth shifts require a longer transition= heat =Bad for tranny. Jus sayin