Thoughts on choosing an amplifier

After much thinking, too much actually. I have narrowed my amplifier choices down to a Parasound a21+, a Benchmark AHB2, or two Schitt Aegirs. Presently, my modest system is a Pioneer PL 71 turntable with an Ortofon 2M Red cartridge into a Schitt Mani into a NAD C 326BEE feeding Quad 12L Classic monitors. Time for an upgrade, eh? I though I would start with an amp and some more speakers. 

The plan is to remove the jumper on the NAD integrated and use the NAD as a preamp until I choose a preamp to go with the amp. For what it is worth, I am leaning towards a tube preamp - maybe a 6NS7. I also plan to buy a few modestly priced speakers, such as Magneplan LRS,  Zu Omen Dirty Weekend, Bowers & Wilkins 603, GoldenEar Triton Five, KEF LS50, or Warfedale Linton, rather than one more expensive speaker. I like the idea of swapping out speakers for fun, type of music, etc. So I am looking for an amplifier that pairs well with many different types of speakers designs.  Which one of the three amplifiers would you choose?

From reading the forums, people often ask the poster what type of music they like to listen to. My music tastes run from Americana to jazz to opera to classic rock to ambient electronic; mostly Americana and jazz tho.

Thank you in advance for your collective advice. It is very much appreciated.
BigMusic - First time poster
I really liked the Parasound I heard (the A23+ driving Spendor towers). The more I learn about Parasound, the more I respect and trust them as a company. If I wasn't headed for tubes, I'd buy Parasound, very likely, unless a Belles or Pass or something higher up piqued my interest.

Nice video here with two key guys, Schram and Curl. Replace dot with . to get the link working.

www dot youtube dot com/watch?v=fZwS-oyqc3w
I owned the KEF LS50 + Benchmark AHB2 + Benchmark DAC3 HGC and it was my favorite setup with the LS50s.

These are the other amps I had with the LS50s

Peachtree Nova 150 (not bad, can listen long hours, maybe 80% of the AHB2 in details)

Bryston PowerPac 300 (same as Byston 4B-SST) (a little hard on the top end). I needed my BAT preamp to smooth out the top end.

Parasound A21  (not much detail and my least favorite)

The AHB2 was my favorite because it was so clear and smooth with more than enough details. That almost invisible noise floor is noticeable relative to the other amps I have listed. Each amp listed was used for at least 1 year with the LS50s. I had either the DAC3 as a preamp or the the BAT VK 42-SE with a Benchmark DAC2.

Thank you very much for all the excellent opinions. I will definitely look into the suggestions offered.

I am planning to replace the Ortofon 2M Red. That may even happen before I finally select an amp as I just bought the "tools" to help me learn how to replace a cartridge myself. I figure as long as I am isolated I may as well try to learn a skill.

Thanks again for the collective wisdom. You're the best.
Big Music
I too have the p5/ A21+ with magnapan 1.7i.  I get a wall of effect but no soundstage.  Try as I may no luck. My previous set was a mc250 with a conrad Johnson tube pre. Lots of soundstage but no dynamics.  Great for jazz but like to listen to many kinds of music.  If you do go with the A21+ get the best tube preamp you can afford. Just mho.
How about a used Audio Research Vsi60?   It's a fun amp with plenty of power, a big sound stage and a lot of get-up-and-go.  I prefer it with the original 6550 tubes,  not the KT120.   It falls in your price range.