Between the two (M10 or M11) I think the M11 is a better option if only because of all the accessories you can get that will really improve the shootability.
When I got my one and only MG, I was also leaning toward a MAC but ended up buying a Stemple. I have alot of guns and (I thought alot ) of ammo in 45. The Stemple came up at a reasonable price so I grabbed it. It's fun to shoot and works great, but I sometimes wonder if I should have gone Mac. The Uzi is nicer than the Macs, but at the time they were a thousand dollars more, and the Stemple with the can was about as much as I had planned on spending on the gun alone. BTW, the Stemple cans are low tech and big but it's pretty damn quiet for a 45 machine gun.
Look into a 22 kit. There are a couple of options for the M11 and I think one for the
M10. I'm in the process of building a 22lr conversion for my Stemple because no one sells one and I have some machinery so, if I can't buy it I'll just have to do it myself. The price of ammo these days makes shooting full auto a rare treat. I shoot my subgun a couple of times a year. Once I can shoot 22 I'd like to make that a much more frequent event. The guys I shoot with (who don't have any full autos) will dig that no doubt.