If you run the PAP you might as well shoot yourself, The only decent woofer they have they stole the design too...yeah.
TSNS is a pretty strong sub - but you said the RD Heavyweight/SuperHeavyweight wasn't near strong enough? 3" Heavyweight vs 4" Coild TSNS the TSNS was a tad louder, but the 3" coil kept up with it, for a fraction of the cost, sounds decent, and wasn't getting hot.
I'm going to tell you this RIGHT NOW though, if you're in fact running a transmission line enclosure, you do NOT NEED 7k rms per woofer. To boot, with that enclosure you're not going to find a subwoofer that will take 7k RMS per woofer.
Best of luck.
Consider the TSNS, RD Heavyweight/SuperHeavyweight, Atomic APXX, SoundStream XXX