If you want PCI-E then im guessing you dont want integrated video. Id suggest this if you can find it on a UK site. Any of these will do well and are relatively cheap.
The best mATX AMD boards are most definitely the Biostar Tforce6100 boards. Unfortunately they are kinda in short supply. If you can find one though...
Given that you get the right board (the non-SE version). The A8V-VM is quite solid. Good featureset for the price. Altho its only a medicore clocker at best.
The two PP suggested would be better, but will prove a right PITA to obtain in the UK.
I havent personaly worked with any of these boards but they where just what others suggested to me when i wanted to make a toaster. Back in those days though i wanted AGP instead so i was SOL. THat board looks decent. Hope you didnt want Gigabit though :/