I have always been a box speaker person with top of the line Harbeths being my preference. Recently, I had occassion to a super! great deal on a pair of Magnepan 20.1's with the Cherry rails. Now, I've never heard a Magneplanar speaker so didn't know what to expect. I went to the sellers home fully expecting to be disapointed but wow, they sounded great. Anyway, it was too good a deal to pass up and now, they are in my home....I must add that the WAF ain't all that great because these things are monsters. NOW, I have the task of properly powering these speaks. I have them hooked up to a single Cary CAD200 amp thats doing 350W a channel and WOW but feel more power could be better so I'm searching for a best fit mono or single amp that will do these justice. A little hard for me because I'm a tube amp person and the tubes I've got just ain't gonna cut it with 4 ohms. Any suggestions would be sincerely appreciated.

I use Pass X600.5s with my Magnepan 20.1 speakers and after many systems in pursuit of satisfaction in this hobby I am extremely satisfied with this combination. The 20.1s do need a lot of power to sound their best so my recommendation would be to go with a good high powered solid state amp like the Pass amps or Brystons as recommended by Recordho. I've owned and enjoyed Harbeths also but I plan to stay with the Magnepans for the long run. Congratulations on the great deal. I purchased mine new through a local dealer and they're a fantastic deal at retail IMHO.
Maggies are a nearly resistive load but draw tons of current. So any high current amplifier will work well.
I've heard the 20.1 sound very good on a BAT Vk-500 and Vk-600.
Get two Vk-500 on the used market and run them as monos. There won't be anything new that would come close for the price.

Good luck!
I drive my 20.1s with Krell fpb 350 monos so they give me 700 watts per speaker at 4 ohms. I love the set-up but would also consider Brystons if given the opportunity. Congratulations on a great purchase. BTW, WAF is low here too but the expensive kitchen keeps us on a neutral playing field!!
Get rid of them, and buy some box speakers that "punch" the bass like you like.....dipoles don't do that. (been there, still doing that).

Bryston, Krell, big Pass Labs, Cary MB 500's, Sanders Sounds Mono Blocks, Parasound Halo JC-1's, Wyred4Sound 1000 MB