What amplifiers should I consider ?

Ritteri

Agree 8008 is very good, especially when you consider the value. Just a combo I believe would be in the ear bleed category due to the tweeter in the Hales. JMHO

Audiogoon is absolutely correct. The Hales are a difficult load, so tubes are probably out the window, particularly in your price range.

I used to own a pair of Hales Concept 2s (predecessor to the Transcendence line) and had GREAT success driving them with a Classe DR-9. You can find these used on AudiogoN for about $1,200. As an upgrade path, you could later pick up another one and bridge them. In stereo, it's 100 wpc, but like the Ayre also mentioned here, it's super high-current. In mono form, these amps deliver 400 wpc and the power doubles as the impedence halves. The DR-9 was famously paired with Apogee Divas back in the day. Most consider the DR-9 and DR-3VHC to be the very finest amplifiers Classe ever produced.

Best of all, the sound is very smooth. The phrase "iron fist in a silk glove" pretty well sums it up.

Thanks for all the responses. Right now, I am still doing research, and don't expect to buy an amplifier until perhaps November. I know what I WANT to get (a YBA 2), but will probably need to reduce my expectations (or wait until tax time). I am leaning towards the Marsh A400s Power Amp, it seems to be a pretty well respected unit, and I like what I've heard of it (although it was NOT with Hales Revelation 3 speakers). The Marsh amp is just inside my proposed budget (Max $2000 US), but I will listen to the PS Audio HCA-2 and the Proceed HPA-2 amplifiers before I make any firm decision.

Kberg: I used to sell Proceed(along with ML and Revel)amps. STAY AWAY FROM PROCEED!! They had a terrible return rate and reliability is very poor at best. In one year the company I worked for sold about 120 units of the HPA and AMP series. Over half of them came back within 90 days for warrenty issues. Madrigal cut some serious corners on these. Solder joints were terrible. If your even thinking about an HPA 2, you seriously need to put an Aragon 8008BB into that list. The Aragon is a far superior built amp and sounds much better too. Tighter bass,smoother midrange,soundstage is much more open. The Aragon is of a true industrial build quality with superior sonic characteristics.

Belles, is great sounding gear. More sophistocated to my ear than the Marsh, and more musical, whatever that means. Mr. Belles hand wires the units personally. Talk about hand made!
The Hales I heard were a little forward sounding in the high frequencies, so the combo of the new 21A preamp (with a couple of tubes, and the 150A would probably do well for you with those speakers. And it should fit in the price you mentioned.
IMHO, as always.
Good luck and good listening,
Larry