Next time, use pcpartpicker for its ease:http://pcpartpicker.com/p/itYq
I've done your build with a bunch of suggestions for changes according to my preferences but arguably on your behalf as well
I concur with LatiosXT in that:
- for gaming, all you need is a i5-3570K
- since you are new to building, I'd suggest going with a great bargain Cooler Master Hyper 212 Evo (or Plus, whichever is cheaper) - if you want to go higher-end air or even water cooling later, decide that as a future upgrade
- 16 GB is unecessary for gaming
In addition, imho:
- I've chosen an ASUS mobo with slightly less features only because I think it's money saved / they are features you don't need. I could be wrong though.
- Samsung RAM is good - google it.
- Seagate 2 TB HDD - cheap and good.
- Carbide 300 saves you $100 over the 600T (and again imho, better on the eyes).
- Seasonic PSU - can't go wrong.
- Definitely build if you are able and willing. It's not just getting a lot more for the same money, it's getting more for less money. It's not plug and play, but the process does actually makes sense. Just have a little patience. A lot of patience is helpful, too.
- Other than a few parts here and there, imho you can't go very wrong because you are dealing with the higher-end. For example, I think LatiosXT is probably right in that the ASUS monitor is better than the Dell. The difference is probably not very big at all though. So things get down to price and personal preference - is the slight edge of the ASUS worth the extra $25 bucks or so? Or maybe you like how the Dell looks better? We can have that discussion with almost every part you or I listed.