Ah grasshopper, you have much to learn :B
Better RAM as in faster RAM (I'm assuming) offers no real benefit. From what I've seen, it either helps integrated GPUs (notably APUs) and compression of large archives. Other than those two things, you get pretty much the same performance. I mean, it may technically be better, but it's always <=1%.
That machine won't eat up any more than 230W if you're not trying to deliberately trying to tax it with Prime95 and Furmark at the same time. Although Furmark now can't cause a burn-in scenario worse than say Crysis 3. Though at worst with 100% load I would predict somewhere along 450W. I can comfortably say this because I have a similar setup, and I've measured 230W off the wall (which with the 80PLUS Gold PSU, it's about 207W for the computer itself). Plus drives don't take up more than a handful of watts at most. You could power all of the drives you could possibly fit in whatever case you've chosen with a single PCIe plug (which is 75W)