to run skyrim at 1920 x 1080 im guessing you just need a gtx 560 ti(or 660) and an i5 processor, and 6+ gigs on ram 1333 mhz or better
i run skyrim at either 6004 x 1200 or 1920 x 1200, cant use eyefinity with the enb mods, cuts my frames in half sometimes(12-20fps), but without enb, i have pretty much every texture mod out there and im getting about 34 fps, every now and then it dips to 25 for a second. reason i suggest 6+ gigs is cuz im hitting 60% ram usage with just my game running. also i suggest i suggest getting a video card with a lot of vram, 2 gigs+, when i still had my gtx 570(1.2 gig version) my frames were seriously dropping(i wasnt even that heavily modded) and the only reason i could think of is because there wasnt enough vram for the high res textures
specs:
cpu:i7 2600k
mobo: asus sabertooth p67
gpu: gigabyte radeon hd 7970 oc
ram: 8 gigs 1600 mhz
ssd: ocz vertex 3 120 gig
hdd: wd cavier black 1 tb(7200 rpm)
psu: cm silent pro gold 800w
i highly suggest putting skyrim on an ssd if u are gunna add a lot of mods, when it was on my hdd, i was looking at 5 min + load times with all my mods, with no mods it loads in about 2 mins on a bad day, now that its on my ssd its usually faster than 1 min.
the only that thats overclocked is my gpu