From a practical stance, I think since you have your SHTF gun with your PS90, you may be better off going the varmint route. But, I also think that half the fun of owning an AR is all the toys you can customize it with. I know that's a big appeal to me. So, it's a tough call. Depends how practical you want to be.
I know I'm gonna go with the tac model with the quad rail so I can add all the goodies on.