You realize that any response time under 4ms is going to be basically identical, right? There's no point in paying for a lower response time than 4-5ms.
I suggest a 120Hz monitor if you're trying to get the advantage in shooters - it does make a fairly big difference.
You don't need two HDMI cables to run at 120Hz. You're correct that consoles are fps capped, but what in the world does that have to do with anything? How do you know the OP doesn't have a PC?