What amplifiers should I consider ?

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

FWIW: If you havn't made a purchase yet, I recently upgraded my amplifier to a Krell KSA 250. this 250 watt class A powerhouse literally took ahold of the hard to drive Hales Rev III's that I have and made them sound like speakers costing 3 times their price. I can't overemphasize how much the improvement was from the bottom all the way to the top end.

What is your experience with these speakers?

Brad