Suggestions on SS/Mono Amps for woofer towers

Looking for suggestions on (inexpensive)the best bang for the buck.. ss/mono amps to drive my 4 ohm Infinity RS1B woofer towers..
Someone has suggested ATI 1502's as the best bang for the buck?? Plenty of clean tight power.

What do you think??
Here's a link to the thread about the Perreaux 5150 driving the woofers of an Infinity RS-1B system. If you do a search, you'll also find several comments about Rick's ( aka Rwd on Agon ) experience with a Perreaux PMF-2150 and PMF-3150 driving his RS-1B woofer columns. Quadophile also has come comments about bass output and woofer control using his Perreaux PMF-3150 in this review of Paradigm speakers. There are also several comments about older Perreaux's in this thread with specific reference made to them working quite well with "tough to drive" speakers that are of low impedance. I'm using two PMF-3150's to drive eight 12 inch woofers ( 2 ohm's per channel ) with nary a problem and thunderous bottom end. Sean

I'm interested in your experience with the Crowns.  I'm looking for mono's for woofer towers of Betas.

How have they worked out?
I have used the Crown CTS2000 amp for subwoofer.  This is an evolution of the same K2 type technology (Class I).  While these amps are very good for the money on the used market, they just did not control the subwoofers as strongly as a very high current Class AB amp.  My Emotiva XPR-1 monoblock is the strongest subwoofer amp I have ever used.  The XPA-1 monoblock is probably the next best thing.  If you have lots of money, the Bryston monoblocks would probably be very good.  Or Parasound JC1.
Big power Class-D they like 4ohms and bass is what they're good at, if nothing else.

Cheers George