Finally Upgrading from Socket A, check my Spec?

[Furton]

Currently running the following

AMD XP2500+ M @ 2.3Ghz
1GB BH5 RAM
DFI LanParty Ultra B
6800GT@Ultra
Seagate 250 7200.9 SATA drive
Tagan 480W SLI PSU

In my basket in at the moment I have the following.

CP-141-AM AMD Opteron UP 144 San Diego 1.8GHz 1MB Cache (Socket 939) - Retail (CP-141-AM)
£104.95 £104.95
GX-044-CO Connect3D ATI Radeon X1800 XT 256MB GDDR3 AVIVO TV-Out/Dual DVI (PCI-Express) - Retail (GX-044-CO)
£179.95 £179.95
MB-014-DF DFI LanParty UT NF4 Ultra-D (Socket 939) PCI-Express Motherboard (MB-014-DF)
£79.95 £79.95
Subtotal £364.85
Shipping (City Link Parcel Next Day (Delivered Mon-Fri)) £8.95
VAT £65.42
Total £439.22

Will my BH5 RAM be okay for this setup in terms of overclocking?
Can someone recommend me a heatsink? I already have a 92mm SilenX fan from the SP-90 I'm running atm.

Any advice, comments appriciated.

 

[Furton]

I think I need that graphics card as I'm running a Dell 2005FPW.

As for heatsink I was looking at either the Arctic Cooler 64 or the ThermalRight XP-90 + 92mm fan.

Also, what sort of clock speeds can I expect from the 144? Looking around it seems to be around 2.6-8Ghz?