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.
Cheers,
BigMusic - First time poster