New and old parts. Are they OK together?

Hello, I'm trying to make a new PC saving some components of my old system.
I don't want to do Overclock, and I'll use it to play (1280x1024) in a 19" monitor.
In the future crossfire could be posible.

The final choice is:
CPU (NEW)
Intel E8400

CPU Fan(OLD)
Zalman CNPS 7700 ALCU
Is it ok with this motherboards?

Motherboard (NEW)
Asus P5Q PRO
or
GA EP45 DS3R

RAM (NEW)
Any 2x2GB DDR2 800 CL4-4-4-12
G.Skill Extreme PC2-6400 4GB (2x2GB) CL 4-4-4-12 - Memoria DDR2 800
or something similar.

Graphic Card (NEW vs OLD)
Now I have a EAH 2900XT 512.
Something new could be a 4850 or a 4870.

PSU (NEW vs OLD)
My PSU is a LCPower 5500w
I was thinking in something modular, but no so expensive. Any ideas?
LCPower Ozeanos 650w

Case (OLD)
NZXT Trinity

Hard Drive (OLD)
Seagate 400gb
Maxtor 200gb
Enough.

Well, what do you think?

PD: sorry about my english