TRU PRO Official

I'm using a gut/poly hybrid. I have been using Luxilon Element 16L which plays the best of all the ones I've tried. I usually string at 48/45. The Element plays well but it only lasts about 4-5 hours of doubles before it stops snapping back. Since I got a bunch of sets for $9.00 each I can't complain. Which Tru Pro poly and which gauge would match up well as a replacement for Element 16L? Thanks!