It comes down to a series of choices. You would go for the pure gaming experience and I am looking for a much more balanced option - looks, noise level, multi-app capability, storage & gaming.
I understand what you are saying, just based on your initial post you were looking for a rig geared towards gaming. The system you configured wouldn't have been top of the line two years ago in that aspect, that one I did would have been king of the hill six months ago. In terms of gaming the rig you have configured quite frankly sucks, nothing against it, and it will be better then your GF3, but it isn't a good or even mediocre machine to play today's games on. You will have to scale back your resolution and details even on games that are shipping right now, forget about a year down the road or so.
For most of your concerns in terms of what you are looking for in your new rig- 512MB is going to be more then enough for pretty much everything outside of gaming. I was running 512MB for some time under XP and would regularly have a dozen to two dozen apps open at once- gaming is the only major issue where RAM is going to be a major limiting factor most of the time.
Noise- the stock cooler on the XP 2700+ is very quiet and cool. TT's HS/Fs aren't the greatest, and tend to be significantly louder then what they are rated at. I would reccomend you look elsewhere even if you don't want to change any other component in your rig. I'm currently running a Volcano11 inside of a XaserIII with a TT 420Watt PowerSupply for the record- I certainly have no bias against TT except that I have repeatedly been let down by their sub par HS/F combos.
You hadn't mentioned OCing much in your summary which is why I went with the 2700+.
The video card in the system represents the main limiting factor in gaming performance. Looking at any system that will be used for gaming the vid card setup should be the most expensive element, and by a decent margin. I can understand your hesitation at spending a decent amount of money on a vid card, but know that going with a 9600Pro you are getting performance that wasn't top of the line two years ago- it already has trouble with today's games where you have to back off the details and/or res and also you are wasting your money on a 256MB board- the R9600Pro is far too slow to utilize the additional RAM.
I would say don't take my word for it, start a poll if you would like to see which would be the better
overall system. Obviously the configuration I have will slaughter the one you have for gaming, I simply don't see your configuration having any significant advantage at all.
I'm not trying to blast you or make you look bad in any way whatsoever, I simply am trying to help you get the best performing machine for your money. I understand your concerns about noise, and with using comparable setups as you have listed above you can move to the case you have selected and it brings the prices on the machines to about even. For that matter, sub out the processor I have selected for the combo you wanted(though I would advise going with something other then TT for a HS/F) and we are still talking about the same price. It really mainly comes down to a tradeoff of RAM for vid card power. I'm telling you in my estimation 512MB is going to be enough for pretty much anything you are going to throw at it outside of gaming which won't really make a difference with the 9600Pro anyway.