Silent and green

Greetings,

Currently my system is like a vacuumcleaner and thusly a plausible cause to my tinnitus and a certain cause for creating high powerbills. This need be stopped. At least to save me from using hearing aid in the future.

Currently I have a
-P4 prescott @3GHz with a IBL 1210 cooler (IBL's own coolers www.ichbinleise.de (older model, isnt listed anymore)), on a
-asus p4c800-e deluxe mobo
-an ati 9800 pro videocard
-Zalman zm400b-aps is PSU
-3harddisks: 2x sata, 1xata

These core components are to be replaced, methinks (with exception of HDDs). I barely use the computers computing power, for I only surf the nets, do office work and watch films.
Occasionally I do some video and photo editing. This however, is done not much.

I had in mind to buy an AMD athlon 64 4450e. But I do not know which motherboard. Preferably low in powerconsumption and having at least 3 normal pci-slots. I do not plan on playing games in such manner that I need to combine two videocards. I do want to buy a videocard though, one passively cooled and of the brand nvidia. Two monitors and a tv is waht I want to hook up on it.

All powered by a silent PSU. Also passively cooled.

All is put in a lian-li pc60 housing (http://www.thg.ru/howto/20050418/images/lianli-pc60plus-total.jpg) with proper airflow.

Im not in a hurry to buy stuff and the budget is medium. I cant come up with numbers though.

tldr:
advice on
-mobo socket am2
-passively cooled gpu and psu

perhaps anyone has ideas or suggestions on the matter.

Thanks in advance.