from most of the mac owners I've heard or read all said that they are happy with their macs' personalities.
you can try shoal macs but it's not as easy as shoaling pygos, it's possible but not every attempt will be successful. I've heard plenty stories started with a decent size shoal of baby macs and eventually down to just a few or some even just one.
if you'll be moving whatever you keep into a 125g in 3 months then I would say try to see if you can get a shoal of caribes, or if you can find a shoal of ternetzis.