I am looking to buy a new motherboard and a new processer. I already
have 2 512 modules of Ram (type 333) and would like to reuse them..
Based on reviews please find the best motherboard out there at the
moment and links to UK websites where I can get it (cheapest). I am
looking to buy a AMD Athlon 64 3500+ processor, so I need a
motherboard that supports that.

Hello Werde

As with all questions of this type being the "best" at something is
very subjective.  What one person may think is the best may not be
what someone else thinks is.  With this in mind I have assessed your
options and checked various hardware websites and the motherboard that
I have found to be the best is the ABIT KV8-MAX3.

I have judged this upon its various reviews, upon the hardware on the
board and its value for money.  This is a motherboard I would like to
own!

You can find full reviews of the motherboard here:
http://www.8dimensional.com/mainboard-reviews/abit-motherboards.html#Abit_KV8-Max3_VIA_K8T800

The board features:

· AMD Athlon 64, socket-754 up to 800MHz FSB. 
· Via K8T800 North Bridge, Via VT8237 South Bridge 
· 3 x 184-pin DDR-SDRAM with single-channel support for up to 2GB's,
PC2100, PC2700 & PC3200 (DDR266, DDR333 & DDR400) DDR memory
· 5 PCI slots, 1 AGP 4x/8x, 8 USB 2.0 ports, ATA-66/100/133 IDE 
· Via 8237 on-board Serial-ATA RAID & Silicon Image Sil 3114
Serial-ATA RAID, 3Com Gigabit LAN controller, Realtek ALC658 6-channel
audio with S/PDIF optical outputs, IEEE FireWire controller
· 2x PS/2, 4x USB 2.0, 1x LAN, 1x FireWire, Audio 

The cheapest I have been able to locate this motherboard is for £70.50
from Komplett.co.uk.  Please note there are several versions of the
KV8 motherboard each with slightly different add-ons, which one is
best for you will depend on your exact requirements.

When you check the price to buy the item make sure the prices have not
changed and gone down by looking at these sites:

http://www.pcindex.co.uk/results_Pro.asp?Category=2&PartDescr=socket+754&id=90965984
http://www.kelkoo.co.uk/search.jsp?catId=100164013&siteSearchQuery=k8v
http://www.dealtime.co.uk/xPP-Motherboards-k8V~CR-1~DW-0
http://www.computerprices.co.uk/hardware/pricebrowser.asp?categoryid=MOBO&testcatid=MOBO&manufacturerid=ASUS&textdesc=Asus

If you have any questions regarding this subject please ask for
clarification and I will do my best to help.

Just like to add a thing:
Since you are going to use a Athlon 64 you realy should upgrade you
memory to DDR400 since the Athlon64 uses FSB400. If you use the DDR333
and a Athlon64 you will reduce the factory memory bandwith in
somethink around 20%, reducing the processor speed conciderably. You
should think about that.
One thig is that ddr333 and ddr400 are about the same price, and you
can sell yous on e-bay with out any major efort. You can also
overclock your memory, especialy if it is from a good brand.