Jerry,
I've been using a Hammer A31 (the 12" model) for well over a year. It's been a fine machine for me. I got, and recommend, extension tables for the jointer and the planer outfeed, as well as a digital readout for setting planer thickness. I thought the Hammer was a better value than the machine made in the country that makes Fiats. With the price reduction on the MM the choice might be a tossup now.
If you are considering a slot mortiser, that attachment works great too. (However, if you tend to do smaller-scale work, a Festool Domino is a bit cheaper than the slot mortiser.)
The 12" width has been adequite since wider boards are getting to be rare. But, as always, if money is a minor issue, wider is always better. Stepping up from 6" to 12" jointing capibility is a huge advantage.