Considering that over half of all internet users will come to your site with Internet explorer, I think its a bad idea to block it right away. Using modern tools and techniques, there is absolutely no point in blocking anything other than IE6 which is ten years old. Especially if you want to sell things. Then it is like opening up a shop in London, Paris, Amsterdam, Tokyo, New York or any other major city, and then only reject all colored peole. You are cutting away over half of your potential customers. I would also recommend fixed width and to remove some of the eye-catchers in red(tone them down, focus on products!), and implement a more traditional looking search where you can see it is a search field right away, not something looking like a button since it tells people they have to put in extra effort to be able to perform a search. Well, the don't have to actually, but it looks that way and that is a kinda hinderence of sort. The search function was pretty cool though