I took some time to re-configer your system. Get it within the current price of this configeration. But I need more information on what your going to use this system on. If its gaming you need a better video card.
Intel Core 2 Duo E6850 @ 3.0GHz
Western Digital Raptor 150GB, 10K RPM, 16MB Cache
Also I like Corsair Dominator Ram's but its you choice.
If not overclocking, the stock cooler will be sufficient.
We still don't know what brand/model PSU you have. If it's a Powmax that came with your case, it's fecal material I wouldn't trust to run an old 386. If it is a brand like Corsair or OCZ it should be just fine.
You listed your memory as 553, is that DDR 550 or DDR2 533? I am assuming it's just a typo and it is actually 533 and if so I would suggest just getting another stick, assuming your current config is 1x1gb, rather than DDR2 800. You can get a 1gb stick of 533 for ~$20 and the difference between 533 and 800 is margainal. You can then use the difference toward a better video card like the one chookman mentioned and in doing so would get a much better return on your money.
My point was that there is very little difference between 533 and 800 and you could get 1gb of 533 and use the extra $30 toward a better video card. You will see a much larger improvement using the money toward a better video card instead of RAM.