LED Monitor/HDTV/GTX 660

Hello,

I have recently built a computer, my first one. Here's some specs:

i5 - 3570
Asus P8Z77 - V
1 x 8 GB RAM (get more later)
1 TB HDD (will later get SSD)
Corsair GS600 PSU
Creative 5.1 Surround

System is running beautifully, so far.

I am planning on purchasing an EVGA GeForce GTX 660 with my next paycheck. I have done a load of research into monitors and hdtvs. I guess my question is: I also own a 2012 LG 42' Plasma 720p, I currently use it as a monitor for internet use, TV and movies, (with a wireless keyboard/mouse) and some gaming (the Intel HD 4000 is pretty usable for some games on low/med quality). The monitor I am planning on getting is a BenQ GL2450 24' HD (1920x1080, 5 ms) widescreen. I plan on using it for gaming. Like visually, will I notice a difference? I understand both are 60hz, but I've heard pros and cons for both monitor and HDTV, distance to TV/Monitor, refresh rates, response times, etc. That overclocked GTX 660 is max refresh rated at 240hz. I can't afford a 120hz or a 240hz monitor or HDTV. Is this going to be a big difference if I game FPS? I also like RTS, 3rd Person games, and will be doing some video SFX/editing with this setup. Casual gamer, not a pro or anything, but I do like my games to look pretty. I understand that if my system is producing faster than 60 fps, the monitor/tv will only display 60 fps?

Any thoughts or suggestions? About the monitor in question? I may put in an additional 660 down the road, but I'd like to see how this setup games first.

PS - Any tips on the flash BIOS thing on this mobo would be appreciated, I have not usb flashed it to the updated bios, yet. Or any newbie tips for me: like I only have the two stock fans in Antec case and CPU fan, is this good enough? Did not put any of that liquid stuff on CPU, I think there's already that grey putty stuff on it. It's decently ventilated, how often should I clean/dust it?