Rebuilding an emchines T2885 ( tossing old hardware out)

(sorry if this is posted in the wrong area tried general homebuilt but wouldnt let me post there)
Im gutting my machine (a older emachines T2885 ) Ive had and used since 2003 , components are getting old fans starting to get a lil louder etc ....

whats currently in the rig is .....
win XP home edition
intel seabreeze mobo.
intel celeron 2.8ghz processor
768mb ddr 333
on board intel 845g extreme graphics 64mb shared mem
a westerndigital 80gb harddrive and a seagate 80 harddrive
creative soundblaster live sound card
DVD player and cd rw

my budget is VERY VERY low
so heres what Im what Im considering

win Xp pro 32bit (already have it)
Am2+ Motherboard (being specific ASUS M2N68-AM SE2 mobo)
Amd Athlon 64 X2 4400+ processor
2gb ddr2 667
on board graphics (geforce 7025 I think)
a western digital 320gig Harddrive
onboard audio
a new psu (looking at a 450watt psu thats got good reputation)
and a lil later adding a DVDR with bluray player

now my comparison question is

im not that huge of a gamer but I do want to be able to do a few things my machine just cant

1. play GTA IV
2. play NFS and so on
3. play other games that have a seemingly heavier load
4. get more than 2 fps when other people are around on second life.
5. surf the web faster my firefox and safari slightly freeze up sometimes
6. doing light web design and graphics.
7. chatting on certain voice chat system etc
8. watching movies and listening to music

Im beleive that my pc performance difference should be like night and day ,

but just how much better is the processor Im getting than the one Im using ?

another question I have is I know I dont need 450 watts but in efforts of less heat would the less strain on the psu cause temps to be lower?

and before saying i should go phenom ,, or intel i stress again ,,, lol that tight tight budget and the intel prices are rediculous for core 2 compared to the amd.

just wondering before I buy if the new processor will do better than the old on a 32bit system

Im keeping under 250 us dollars but maybe under 200 (far fetched I know the harddrive prevents that though

and yeah I cant go with a gtx 200 series but , later on maybe a 9 series (case is too tight for enough airflow to cool. )

Get this for your PSU, it will be plenty:
http://www.newegg.com/Product/Prod [...] 8&Tpk=370w

Ram:
http://www.newegg.com/Product/Prod [...] 6820145184

I highly suggest you get a better processor, I feel like $40 for that 4400+ is a waste. This one would do well and it overclocks better, and the bundled mobo has support for other phenom cpu's so you can put one of those in when you want to upgrade, and it has the best onboard graphics chipset:
http://www.newegg.com/Product/Comb [...] mbo.172781

HDD:
http://www.newegg.com/Product/Prod [...] 6822136074

Total of that comes to $300 free shipping and you get $25 MIR.

^+1 u cant get any better parts than tis...

U can also upgrade the CPU later to any new Phenom II because all AM2+ mobos, can support the current AM3 CPUs...
So u are can upgrade too...

And the PSU can also handle discrete grpahics card (mayb even a 4870)...

Yes but it was over his budget. The first setup I had was much better, but if he can't afford it then it doesn't matter if its a better value. That mobo will still allow for phenom II CPU's. Although that first setup was only $14 more...Idk. If you can afford $275 after a MIR, then I highly suggest you go for that first build I put together, I think you will wish you spent $14 more later on. Maybe save up for a week and then try?