Generally I'd say go back to the regional, given current pay scales and your seniority.

However... legacies are currently metering hiring from their affiliated regionals, a lot.

If your regional is AA only, great, apply to DL and UA. But if your regionals flies for 2 or 3 legacies, then you should do some research on the state of metering, and also consider which legacies you'd prefer.

All the legacies will hire from 2nd tier/ULCC without any reservations. You already punched the PIC ticket, even if only briefly, but that's more than many legacy new hires can say right now. Given your background a fresh NB type and a few hundred hours online should get their attention.

There's also something to be said for going back to a plane you already know, returning after that long of an absence is not trivial (nut two years is better than ten years).