Comparing a M29 to a Epoca is like comparing apples to oranges. Now comparing a M29 to say a Rancilio Classe 8 and now your on the same playing field. The M29 is the middle ground machine for Cimbali and the Epoca is the starter model for Rancilio. From past experience the Epoca is a great machine to start with if you go into it with the idea you plan to upgrade as you expand.
Every thing about a M29 is just beefier then a Epoca. The both have the same boiler size roughly but the M29 has a much larger element. Also the M29 can be ordered in a Tall machine so you can put 16 oz cups under the group head. There are a few technical aspects that make 6 month PM's a lot easier and less time consuming for the operator for the M29.
I like first started out, I would highly recommend that you look in the Classe 8 if your looking for something comparable to the Cimbali M29.
As for the grinder Cimbali's are good. I think Mazzer's are better but that's just my opinion.
I agree with CCafe- cimbali M29's have a stirling reputation because they have been around as a commercial machine for so long. Cimbali is, whether the rest of us like it or not, the standard setter for commercial machines in this range- it is a solid machine. I am no fan of Rancilio personally, having worked on them in NZ. They are OK, but if you have a choice at around the same price the M29 would be my pick.