Check out
this thread in the RRA forum about the TCH.
For the EOTech, you could sell or trade your TCH for a RRA Dominator, sell your TCH and buy the new RRA BUIS when it's available, or you could go with any of the other available BUIS options.
The best thing about doing it one of these ways is you don't have to "ditch" your optic to switch to irons. You just look through the EOTech like it's not even there.
An EOTech on top of the TCH is going to have a TERRIBLE "chin weld" at best, and it's just not a good combination in general.
I run a Dominator on one carbine, and an ARMS #40 with EO on another. I am fond of both setups, but I prefer the folding rear for the slightly less cluttered field of view.
I almost went with a folding front sight too, but chickened out because my fixed FSB is free