Which is the best amplifier or the best choise?

I have this equipment. Cd Oppo BDP 95 with Benchmark 1 Dac; Preamp with Pass X1; Keff 205 reference speakers 200 w at 8 homs and Theta Digital Dreadnaught II amp; All wired with Cardas gold reference interconected and electrical. I love Rock and Clasic Music. My room is not so big. I want to change the amp for some better. I want to buy some A class used and I have this options:
A) xa.5 Pass 60 wats monoblocks
B) Halcro Dm38 class AB , 180 wats
C) Mcintosh 501, 500 wats clas A

Which would be the best choice for you and why?

Thank you un advance for your coments.
Keep your amp. Its the best component you have. I would upgrade something else like your preamp or speakers. How many channels are you using?
You may want to try running your amp in a different configuration than what you have now. Use 4 channels instead of 2. Get another pair of speaker cables and use 2 channels on your Theta for the highs and 2 for the lows. Doing this will allow your speakers access to a lot more power. It will be much cleaner sounding as well. You will basically be doing a vertical bi amp but you will only need 1 amp instead of 2 due to the fact that your amp has 4 channels. You should be very happy with the results.
No, I want to chage the amplifier, I am bored. I think an Halcro is cleaner and more acurated. Maybe I will go for that amp.
If you are set on buying a new amp, go for it. That said, I concur with Zd542, with the bi-amp approach.