If you want features and good value for money i would also consider Abit and MSI.
Heres a bundle for you
A64 X2 4800+ 2.5Ghz Dual Core - AM2
http://www.ebuyer.com/product/134571spend a few £s more and hike that processor speed up
ABIT KN9S Motherboard
http://www.ebuyer.com/product/110803Corsair 2GB Ram (2x1gb) PC6400
http://www.ebuyer.com/product/98710I actually use this setup atm, it rings in at £150.03 (choose supersaver delivery and its free)
Benefits, dual core, ddr 2, sata and ata support, quality products.
You dont need to spend £150, just go for a big name mobo, you can save £s for selecting a different chipset, i used nvidia in this bundle. Processors you have a varied choice i would say AMD they are well priced for a dual core, you could drop down Sempron and save more money, i cant comment on them never used them, you can also go for generic memory but its worth paying a few £s extra for quality.