Here's what I would do-
1. Ditch the Enermax Case, I have the same one, the airflow sux. The PSU wasn't strong enough to power up my old Shuttle Kt266A board which is pretty picky on PSU's. I would get something like a basic Maxtop midtower, which looks similiar but has far better airflow and combine it with an Allied True 400W PSU, total would be $30 (case) + $33 (PSU) = $66. BTW I replaced my Enermax PSU with an Allied 300W, works fine now, and I also have an Allied Ture 450W powering my main rig, nothing but rock stability.
2. You can get two sticks of Crucial PC3200 256MB for $45 a piece,
they overclock much better over Corsair, and can run timings up to 2-2-2-5. If you go with the Crucial, you'll save $29, you can add that to your video card budget
.
3. The Geforce TI 4200 performance is really getting "outdated", I would spend more and try to get a Radeon 9500 PRO OEM or even a Radeon 9600 PRO, both run for around $170-$180. Or an even better option would be getting an OEM ATI Radeon 9700 for $199 from mwave and overclock the crap out of it
. You can get an Abit Siluro TI4200 64MB for $84 at excaliberpc, and save up for a much faster video card.
Everything else looks good.