According to my little experience, it might be better to choose speakers which suits for your preference first and find an amp that can drive well the speakers.
Have you gone to DMT or Tsang Fok to listen to Mytek before? I think Mytek matched quite well with Genelec (active) speakers. If for 20K, you can buy 8040a. If for amp alone, since Mytek has balance out, it might be better to find an amp to have balanced input, like Yamaha A-S2000 (but I have no idea whether they match or not!!).
I just encounter this problem too---my new speakers is much more 大食 than my previous ones. My old amp (20W x2) is not powerful enough to drive them well. I am still looking for an affordable amp which can drive them well and reveal the potential.