Hi there,
First thing I'd do is swap the E8500 for the E8400, saves you £10 and will clock to the same speed.
Unless you plan on overclocking past 4.0ghz, the cheaper 6400 ram should be enough, and is half the price. If you need the 8500 ram, then G-Skill is a good set to go for.
I've noticed the cooler you've put in is out of stock, other suggestions for a CPU cooler would be tuniq tower, noctua NH-U12P, thermalright TRUE.
I've seen review of the biostar I45 and it seems pretty impressive, a lot of overclocking features.