I'm going to set up on of my AR's as a tactical shoot/three gun type of gun, with the capability for short and long range shots, i.e. a red dot/holo sight of some sort, as well as a scope. Now, I'm thinking a scope on top and a red dot off to the side at a 45 degree or so angle would be ideal. Here's my questions:

1. Aimpoint or Eotech? What makes one a better choice than another?

2. Who makes a mount that allows for mounting a red dot/eotech cocked off to the side of the rail/handguard?