The motherboard you suggested should do. The disadvantage is that it doesn't support DDR2-800, so you won't be able to upgrade to faster RAM later. Since you're not overclocking, this isn't a big deal; 667Mhz RAM provides enough bandwidth.
I still suggest prioritizing the video card over the 2GB of memory. You'll notice a much larger improvement spending the money on the video card. Moreover, you can easily get another GB of RAM anytime later, while upgrading a video card implies selling the old one.
Also, an E6400 is not worth the extra £20 in my opinion. Let's stick to an E6300.
: Core 2 Duo E6300
: Asrock CONROE945G-DVI i945G
: Elixir 1GB DDR2-667 C5
: Sapphire Radeon X1950XT 256MB
: LG 18x Dual Layer DVD+/-RW/RAM Black
: 530W HiperPower Type-R Modular Black
: Akasa Zen Black Silent Cool ATX
, VAT included.
Remarks: no hard drive, monitor, mouse, keyboard or speakers.
That X1950XT is a beast, as it seems to beat a 7950GT. It'll last you a couple years before becoming outdated. We had to sacrifice 1GB RAM, RAM speed and motherboard quality, but I think it'll be worth it. If you wanna save a bit more, downgrade it to a X1950Pro or something similar.
As for the PSU, I still prefer the HiperPower Type-R over the ones you proposed. It is rated at 530W, and has dual +12V rails rated at 20A and 17A (37A total). The Seasonic 430W is nice too, but its +12V rails are rated at 14A and 15A (29A total). The HiperPower simply delivers more power at only £3 more, and it is modular too, which is nice to have. More info on this PSU at the manufacturer's website
The DVD burner is your choice, really. Most burners cost around £20, so just choose whatever brand you prefer, it doesn't really make a difference.