whisk what i would do is head over to newegg canada web page and make a gift or temp build sheet and do a print screen and post it here. right now hard drive and ram prices are high one do to flooding where most of world hard drives were made and two one large ram vendor went under last week. your looking at intell x68 or z77 mb the z77 mb will be out at the end of the week. the z77 mb will take both sandy and ivy bridge chips. the i5-2400/i5-2500 are runing around 180-240.00 online and at company like micro center. 1tb drives on newegg are 109.00. a 8 gig ram kit is 40-60 on new egg for two dimm kit. a dvd-burner is 16.00 if you want to watch/burn blue ray a blue ray burner is 80.00. in your price range is nvidia 560ti or the 6850 or 6870 the ati cards are about 20.00 diff in price. i would look into the 6870 and use the savings over the nvidia card for a os ssd.
you want to buy a good ps that has one large 12v rail. a 700-750w would be over kill if there one on sale grab it. a good 650w will be fine for one card system. http://www.newegg.com/Product/Product.aspx?Item=N82E16811121096
copy of the roswell case. as you see has top fan to pull hot air out..all i would do add one in the front on back of the case to pull cold air in.