yeah, but the antec 300 currently doesnt have any good PSU combos with it, the combos make up the price difference between the cases and a bit more generally. Also if you are considering overclocking to 3.6 then you are going to need the extra airflow, i am considering getting the 2 front fans for mine as i got the 300 before the 300 illusion was available.
Thermalright IFX-14 with 3xScythe SY1225SL12M
Prolimatech Megahelms with 2xScythe SY1225SL12M
I use one monitor for gaming while I surf the internet on the other one. I like to multitask. If you have any suggestions on different parts I'm open to hearing them.
On your case selection and Cpu HSF Cooler choices, you should get a case like one below or Antec 900/900v2 or 1200. Main reason is the height of the Cpu Cooler might interfere with you being able to close the side panel on case and airflow is better in the cases I mention for Core i7.
+1 on yoosty's suggestions, antec 300 sounds bit cramped for the spec. esp if you're going to oc and put gtx275, you'll need a bigger case for heat/space. HAF922 is a good choice. I personally have antec 1200. I also have prolimatech megahalem. well i feel that going raid isn't that much better these days anymore. i'd say get 500gb-1tb of WD Caviar Black for now and wait couple months until new X25 SSD to go down in price and use them for OS/Primary Programs. That's what I decided on.