Which mono power amp would you choose and why?

You may want to look for a Hegel H30 on the used market.  The advantage being this 1150 Watt Mono Amp can also be run in Stereo mode with a flick of a switch on the back panel.  Should meet your power requirements today and leave you the option of picking up a second H30 in the future.  Then you could run them as mono amps or as two stereo amps for bi-amping your speakers.  Terrific amps with multiple configuration possibilities. 

@bigtwin 

That Hegel H30 is nice but out of my price range at $15,000.00 each.

@arcticdeth I have looked at the Sanders mono block amps previously but like the Hegel they are out of my current price range at $14,000.00 per pair.  My budget is only around 7K to 9K for the pair not each.

 Thanks for the suggestions and I'm always open to new brands that I haven't considered, but right now I'm limited with my funds, but if things change ( I win lottery or rich relative dies and leaves me money), then I can look at the higher end gear.

Patience, search, and be patient , the Magtech will show up, then send or drive to Roger In Colorado, will make you monos from the stereos. Would be much cheaper that way. Or maybe Odyssey kismet monos. 
audio by van alstine has a deal;now,  monolocks and a pre for 5K  

check out the AVA 7500 m onos

@arcticdeth 

Thanks for audio by van alstine  info, I'd rather keep an eye out for the Magtech amps. The Odyssey amps don't have the power I was looking for.

Just keep the suggestions coming. Time for sleep here in Illinois, just waiting for the snow and -25 degree weather to arrive in 2-4 hours.

@alucard19 - not sure what power you are looking for but watts mean nothing.  I just finished upgrading a Spectral power amp.  To me it was nothing special and rather boring in stock form.  Once upgrading the amplifier, it was another level that I would even consider buying one and I am a tube guy.  In my 20 + years of modifying gear, the upgrades sonically take components to a entire different level that the stock products offer.  You may want to consider something like that and have it upgraded.  Happy Listening.