Corsair is pretty much the top memory brand. Mushkin is up there with them. G.Skill, OCZ, & Kingston and some others I'm forgetting are good as well. But most memory is fine. It's not as bad as hard drives or motherboards where some are just bad.
LG is generally a pretty good electronics company. I've never heard of a DVD burner that doesn't work and the general consensus is the cheapest one is best--brand doesn't matter. Sony's fine too, but not worth any extra money.
Coolermaster makes a lot of bad PSUs.
Get an Antec, Corsair, Seasonic, XFX, or Silverstone PSU. Antec Basiq (the BP and V- codenames) aren't as good as typical Antecs.
If you have a specific part you think is better than what I recommended, post it and I'll let you know.
Don't spend this much on a new computer when your primary focus is gaming and not get a gaming graphics card. If you spend less than 10,000, your card will really hold you back.
If you're not gonna get a decent graphics card, just skip the graphics for now. Your Integrated graphics can almost (almost, not quite) keep up with something terrible like a GT 430.
i3 for gaming:
http://www.anandtech.com/show/4083/the-sandy-bridge-review-intel-core-i7-2600k-i5-2500k-core-i3-2100-tested/20
Yes, the i3-2100 can game. The i3-5XX aren't nearly as good and use a different motherboard.
You can't go much cheaper on parts than I'm recommending since the websites you gave me don't have AMD parts. If you go cheaper, you'll have to get a dangerously bad PSU.
I made a mistake on the RAM above. I said two of that RAM. I meant one. It has been corrected. That could be swapped for 4GB (2x2GB), but I'm trying to leave you a free ram slot for a future upgrade for the same price.