Ballast???????????????

I have just bought 2 600watt 5inch cool tubes and need to buy a ballast for each.

I would like to get electric and have seen that Lumatek do a dual version which incorporates 2 600watt ballasts in one housing.

I live in the U.K and can't find a supplier or a reasonable price.

If anyone has info on good ballasts and can reccommend ones that are silent and energy efficient and don't cost the earth (if possible) it would be cool if you could help me out.

Thanks