The 700R4 or 2004R built correctly will handle 500HP.
I'd go with a well built 2004R. Easier swap, no 1st-2nd gear spread problems and will handle more power than the 700R4 when built correctly.
If you're serious about Strip use, a Non-Lockup TC is the best choice.
Non-Lock TC is much more efficient than running a Lockup TC when not locked & much lighter. Locking @WOT shifts requires a PI 5-disc lockup clutch TC. Single disc TCC can't handle WOT.
There's only about 150-200rpm difference between Locked & Unlocked TCC while cruising. Many of the PTC brand Non-Locks only have about 3-4% slippage up top. A Lockup TC would be more like 15-20% slip Unlocked. :shock: