Something like this
should meet most of your requirements. It's a little over your budget so if you can't afford it you can leave out either the SSD or the monitor.
One other option if you're ready to buy now is that if you get the motherboard from Newegg (same price as Amazon but adds $7.50 shipping) it comes with free 8 Gb of GSkill RAM. If you can live with that (for a while at least) you can save $70 which takes the build right to your $1200 limit and lets you keep both SSD and monitor.
Nice build. In all main components (except I was leaving out monitor, as OP can "work around" that), identical to build I was doing. The only slight area of doubt I would have, is that I've heard of some reliability/warranty issues with Seagate. Was intending to offer the more expensive WD Caviar Black, but whether the better warranty is worth an extra $20, is of course debatable. There are savings that can be made, if necessary, like CPU overclocking, but build best meets OP's wish list.