Arcam PA240 / Anthem MCA225 II / Parasound A21+ ?

What is it you’re trying to accomplish by replacing the Mac?

Of the amps you listed, the Parasound likely has the best build quality. However, for what it’s worth, myself and some others prefer the sound of the original THX-certified A21 to the A21+. The Plus is higher in noise and not as smooth in delivery (also measures worse aside from power output).

Further, the A21s have a distortion signature that is primarily 2nd-order, which is rare among solid state amps, and IMO, superior to many amps which have a primarily 3rd-order harmonic. 
 

But all that aside, I could not say whether an A21 would be more than a lateral move from your Mac. The A21s might provide a more authoritative sound but otherwise sound more similar than different to your 152. 

At least for the Arcam and Parasound you are picking amps in the "warm" sounding range, which is kind of my preference as well but you may want to listen to something radically different as well, depending on your budget.

If you are coming from a Mc, this may be just what you need.  I'm not sure what your power requirements are or budget, but I do suggest you consider a tube amp as one of your listening choices as well.