Get the Low Profile version of the Vengeance RAM so you'll have an easier time installing the coolers. There is no performance loss whatsoever.
I don't really like Seagates, they have a history of a mass failure.. I would suggest you get the Caviar Black from Western Digital. Much more reliable, and it has a 5-year warranty compared to Seagate's 3.
Everything else is good to go!
If you have an questions, feel free to ask.
Even a Hyper 212+ or an Enermax ETS-40 will do the job for cooling. I'm sure you can find a cheaper DVD drive from a lesser known bramd. You might want to consider a 240/256GB SSD if you want to store your applications/games on the SSd too.