[pauldodman]

If you approach the project in the right way - you can do pretty much what you want with x-cart. By this I mean, if instead of saying how do I make my design fit x-cart, you say, how can I make x-cart fit my design, you are half way there. There is no reason why that design can't fit into an x-cart site. There are css menus available that you could customise to do the navigation. Not that they would do the bit where the selected category moves into the left hand column in that way off the shelf, but it may be a good start.