Hey Michael,
What do you think about pairing the HIP's with a couple of Wharfedale dlx15b 15" passive subs? They are similar to the kp-115sw that Klipsch used to make. They have a range of 38 - 2000 Hz, but they have a passive crossover at 150 Hz that can feed a full range cab from the same amp channel. They run in either 4 or 8 ohms, and they are rated at 700W continuous. They can also be bi-amped.
I recently picked up a pair of black painted birch HIP's for $200. I'm also looking at maybe getting one or two used QSC EX1300 amps to drive these. I'm slowly putting together a small PA system to do small gigs and, heck, just to have fun with in the garage! I've run FOH sound for churches and for concert artists for about 25 years now, I still like to play with this old equipment, though!
Let me know your opinion on the above setup. Thanks in advance!