Why limit yourself to a 17"? You could get a 19" or better for just about the same money!
The market will have changed considerably by January so I recommend making another thread like this then. New faster products, especially in CPUs and graphics cards, will be out and prices will be significantly different.
EDIT: Are your current hard disks and optical drives SATA or PATA? PATA is on its way out and most mobos only have one such port. it will effect your motherboards choices if you're adamant about keeping more than two PATA devices.
if you left out the sound card and dropped to a P35 motherboard (P5K) then you would be able to afford a 22" Samsung gaming monitor such as the 226BW, and a decent PSU (e.g. corsair) for your budget.
...what would a 3Ghz overclock up to on air...
Too bad i didnt tell you againWhoops, that's twice in two days that I've done that.
Yes. That's why so many people on forums like these encourage people to overclock their stuff rather than getting ripped off by paying too much, i.e. Don't get an E4500 because an E2180 will do just as well.