High Efficiency, High Power Handling?

The background: my HT room is 34x17, with a drop ceiling, drywall walls, carpeted floor.

System is...

Denon 2803 (center and rears)
Hafler DH-500 (fronts)
Hafler DH-225 (sides)

Speaks are Infinity Entras - the tall two-woof version in front, the large center in the middle, then the one-woof versions on the sides (on top of a pair of 3' high bookcases), and the rears are a pair of the small centers dropped from the ceiling.

There's a pair of subs - homebrew 5.5 cubic foot ported 18hz with Dayton Quatro 15 drivers, each with a 240 watt plate amp. Subs and bass shakers are run through a Behringer feedback destroyer.

Can't really get the volume I'd like for stuff like concert videos, etc... Maybe I've been hanging around my buddy the drummer too much... My upstairs system is a pair of maggies and a pair of subs and is for music - the basement is for music and rocking. When I turn things up, things just sort of run out of gas - it's like I don't have to worry about clipping, because the 2803 just doesn't wanna spank the amps that hard...

Anywho, I'm thinking of trying to do some pro-sound component speaks. I'd like to hit around 100db efficiency, and a minimum of 250w power handling. In addition, I want the drivers enclosure-protected against overexursion - no oversize enclosures - I'll live with the bump... Again, this is for movies, not music.

Right now I'm thinking something along lines of a pair (or four...) of Eminence 8 or 10" drivers (Betas?), and a horn tweeter. I do not expect the system to see a lot of low-end signal. I plan on setting them as small, and adding another pair of the Quatro15 subs (which are currently sitting in a closet...).

So, what would you guys recommend? Without going nuts on cost? After all, I'm looking at 7 speaks here... I've got enough amps that I can biamp/active crossover to a degree.
Bogie, I've had similar thoughts myself. What about the Adire HE12 kit? I believe they have a new XBL2 version coming out of the midbass with much higher excursion, about 95 db efficiency in the midbass, 250watts power handling. If you do a sealed box crossing at 80 Hz with the XBL version (I think it has 11mm xmax) then you reach excursion limit at about the limit of a decent 250w amp, and then can cross to a sub. This system along with a decent sub like my AV12s can hit about 120 db, although its probably more like a nice clean 105 db done easy at a 3-4m away listening position. It's also quite compact.