Decent moderate priced speaker for large room

Take a look at craigs list for your area and see if there is any older Klipsch for sale. La Scalla or Bella. Local sale would be the best because of shipping cost. Good Luck!!

Also look for some older Snell speakers, or older JBL's.

At what price would you not lose sleep over?

I also own a vacation rental. It's impossible to underestimate the level of care (read damage) tenants provide (read inflict). I would get a used AVR or all in one, w some party-hardy speakers and lock the good stuff away for your own use. Maybe a used pair of NHT floorstanders. There are lots of replacement parts available and they actually sound pretty decent. The great room in my house is not nearly as big (L shaped, maybe 25 x 20 with a 10' notch cut out) as yours and I use an NAD 5.1 all-in-one (L-70, IIRC),4 NHT Superones, a Supercenter and an old NHT 10" sub. I am always pleasantly surprised when I get to listen after the tenants leave. That rig probably does not have enough oomph for your space, but if you scale it up appropriately, it should do just fine for parties, background music, HT use. I keep a small BR system locked away (93 dB Zhorns, Bering micro-Zotl, Sony S7000 and HD-650s) for when I need my audiophile fix.

Older mirage speakers can be quite dynamic and sound amazingly good for very little money the money.

Consider Aerial 10t

Get a really big pair of Klipsch or Polk floorstanders. Most of your male tenants will think have died and gone to heaven with these "awesome" speakers, and you wont cry when listening to Jimmy Buffet with Margarita mix dried onto the drivers and few scratches in the vinyl cabinets. I might also suggest a pawn shop receiver in place of your PS Audio... just a suggestion.

There is a pair of Coincident Triumphs for sale $650. Very efficient (92db) so power is of no real concern. Excellent low level resolution. My pair did not come with grills however, so if that's necessary you will need to check with seller.

The Klipsch are a naturally good idea - get the biggest model you can afford. Also, most of the horn-loaded, larger JBLs, old Atlec-Lansing speakers, and the like, plus Cerwin Vega speakers, are other high SPL, high efficiency brands.

Another idea that should work would be the DCM TFE200. At $1K/pr, they are efficient, and I heard them in a large room fed by a 25 watt tube amp. They were plenty loud and dynamic, so with your big room and big amp, maybe it would be a good fit. I think they have a 30-day home-trial so if they don't work, you cen return them. Here is a link:
http://www.mitekfactoryoutlet.com/products/brand.cfm?Cat=18&Brand=6&ProdType=18

PSB Stratus Goldi. They will work well in a large room and with your amp they'll play really loud and should take a lot of abuse without damage unless you change to a smaller amp and run out of power. They are great party speakers and pretty good at lower levels.

Thank you SO much to all of you from the AudiogoN community who took the valuable time out to respond to my inquiry. I appreciate enormously...all of your advice, your understanding and great sense humor, where applicable!

of all of the thoughtful suggestions above, i'd go with the psb stratus golds, which i regularly see used for <$800 or so. they're great and timeless-- might be the best blend of big party-hardy and finesse at that price. alternatively, if you can find some polk rt1000p or rt2000p (which have built-in-subs) for a couple of hundo, they're suprisingly good sounding--more detailed at the high end than you'd expect.

I heartily second the PSB Stratus Goldi - prices on the used market hover around $1100.