Looking for great Amp for Martin Logan Prodigy woofers

I am rebuilding my audio system; centered around getting the most out of the Martin Logan Prodigy.  I have Audio Research VT 100 (intended to drive the panel section).  Now I am looking for a second amp (stereo or Mono blocks) to drive the low end.  I've seen a lot of people using McIntosh, but I am not going that way.  I want a used, well-built and rugged, yet musical amp, (like the Krell FPB 300).  The budget is $2.5k  Does anyone think Krell is the way to go? Suggestions please.
Thank you
In regards to the M-1’s, those amps got a horrible review because the pair that they were sent was completely new without being properly run in.  The amps are a minimum 300 hour break in and will actually sound worse as they play and after about175 hours they will finally start to crawl out of the hole and begin to get better ultimately surpassing how they started after taking them out of the box.  They probably we’re at the lowest point around 150 hours when the review was written. A properly broken in set was sent after and I believe there was a small rebuttal that was posted, but the damage was done and the”audiophile” community avoided them.  Many dealers use those amps to run passive subs, even over one particular high end in-wall brand who makes their own amps.  It was a good learning lesson and every product that has ever been reviewed after has always been properly broken in before sending to a reviewer.  Thanks!
Thanks for the clarification. I read that bi amping the Prodigys is an impossible task because it will never sound seamless while using one amp  for the panels and a separate amp for the sub. Any thoughts?
I did a passive biamp using two Adcom GFA5802s on my Ascent i hybrids and I was happy for several years. When it came time to upgrade the amps I went to a single Pass X350 and still haven't looked back.

I guess my point is that one really good amp might be better than two mismatched amps. Doesn't mean that won't work. You won't really know till you try. There's probably a magic combination waiting out there somewhere.

Good luck
theaudioman; Sorry, I missed the part where you gave your budget in your opening post, which would rule out the M-1’s

Overall, I would say that you’re better off with one or a pair of better mono amps vs trying to run one amp on the highs and something different for the lows. I would try to do two of the same amps, which in this case would be adding another VT100. 

A better sounding amp is just that - better! The VT100 will run your Prodigy’s fine and I don't know if putting a Krell on the bottom will really give you all you're looking for. Something you could consider is upgrading your speaker cable and having them made in a bi-wire configuration, unless you like to change and go through cables, then it’s usually easier to sell non bi-wire versions.  Just my opinions...


They xover at 250hz, so just a Class-D for the bass will be fine that’s what their good at fast dry bass should match up to the speed of the esl's better.
Also get one with input level controls and that has higher gain than your esl amp, as you’ll have to match up the gains.

And it’s also good to have level controls on the bass amp because on hot humid days the esl panel looses a couple of db efficiency, and the sound "can" get a touch bass heavy, but with the level controls you just back off the bass a touch on those days

Cheers George