Decent moderate priced speaker for large room

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.