I doubt very much that you are going to get good performance out of either machine given your required config. You probably really need MacPro towers to do this properly.

-Mac-mini doesn't like to do more than single output typically.
-Macbook might have slightly better performance with "dual" outputs via DH2G, but with that many layers and mixes at your specified resolutions I wouldn't expect as much performance as it appears you require.
SSD over HDD would be critical as well in all cases.

Best bet is to try one out and see if it will do what you need it to, but I'm betting you need MacPro.

Hope this helps.