Oh, by the way... I suspect the STX would drive the FA-011s "sufficiently." Excellently, for quality music listening? No idea. But well enough for any games I've heard? I suspect it would work out pretty well, especially if they claim they can handle 600ohm cans. I wouldn't worry too much about prices... I personally think the headphone amp market has a lot of long-past-the-point-of-diminishing-returns in it. Is a $1000 amp better than a $200 amp? Probably. Is it 5x better? Not likely. 2x better? Not likely. Amps are all pretty darn good, from what I've seen.
I just picked up a Bravo V2 mini tube amp off of ebay for the office. It drives my DT990s and FA-011s with authority. It cost me US$35 (plus shipping). It's being fed by a Behringer UCA-202 (I think -- the $30 USB interface). It's not quite as clean as my E7/E9 combo. But that combo is also just over 1/4 the cost of the E7/E9 combo. And it's way more than 1/4 as good. Probably 90-95% as clean and precise. I would be perfectly happy to play games through that mini tube amp, but I brought my E7/E9 home anyway, for music and movies. Just something to think about. If you're the Golden-Ear type, then you should probably ignore everything I say anyway ;). But if you're not, I wouldn't worry too terribly much about mid- to high-end gear.