www.ebuyer.com
www.aria.co.uk
www.microdirect.com
www.scan.co.uk
There all good competitively priced outlets
Depending on how much your budget is, if you like Intel PC'S go for a skt 775 set up.
If you like AMD go for a skt 939, basically the fitting between the Motherboard and the processor.
There the latest fittings the two CPU giants are offering
If you want your machine for gaming i would suggest a amd Athlon 64 (939) 3200 (Venice core) or upwards
More general application stuff an Intel set up will be better however there a tad more expensive
Post up a ball park budget or some ideas of your own and am sure we can make further suggestions about other components.
My advice would be to look at it like this
1. Think about the above set up - AMD or Intel
2. Processor speed, 3.0 GHz Pentium at least or 3200 amd 64
3. Mother Board (Spend as much as you can on this component)
4. Power Supply, 400w at least (There are two fittings now 20pin and 24pin, see which your chosen motherboard takes)
4. RAM (Check Motherboards support speed and fittings) 512mb at least
5. Hard Drive, go for SATA (Faster than IDE) most new motherboards will support SATA. You may be able to use your old ones? Allot of Motherboard support both IDE and SATA
6. Graphics, APG or PCI-E, again the type of motherboard you have will determine the fitting (Most probably PCI-E) NVIDIA or ATI, this is entirely up to you
7. Case - personally pref, if you already have one think about using that? I did and sold my old parts to a mate.
8. 5.25" Drive, DVD and CD's etc... Again that’s personal pref, Sony are pretty good in this dept though. Or you could use your exsiting ones?
Hope that helps, give us a shout if you need more help fella. I just built my system so its all fresh in the memory!
Take it easy
Mikey