Question About TV Size + Computer

Welcome to the DS forums Slizeezyc!   Nope, I don't think it would require a very elaborate system to run PC games on your big screen TV if that's all you wish to do.   

Everyone has their own personal idea of the best viewing experience & favorite panel size for PC gaming, but in terms of the resolution you are demanding from your PC graphics card(s)...your 65" TV (and most common computer monitors) will only display 1920 x 1080 resolution.   There are much better monitors that can display higher quality resolutions of 1920 x 1200,   2560 x 1440, and 2560 x 1600 that would be more demanding on the graphics cards than your tv screen because they can display more pixels on the screen.   That's why monitors are a bit more desirable & popular for PC gaming, but lots of folks do use TV screens.

Most of the gaming computers you would be buying from Digital Storm will already be fairly powerful gaming systems.... Your desired frame rate target (30-60 fps) at a certain resolution will determine how much graphics & computing power you will want to buy.    Some games will also be more demanding than others on the graphics cards, meaning frame rates also depend on what game you are playing.
Figure out what your screen resolution preference will be in gaming, and what games you want to play at 30-60 fps, and then Digital Storm can help you select a system that has the right combination of components to meet or exceed those performance needs. 1920 x 1080 will be the most common display resolution used by gamers, a pretty easy target for the least expensive DS systems to hit.   Hope that helps get you started.