custom template and menu development for shopping cart site

one of our client needs. custom template and menu development for shopping cart site we prefer interspire shopping cart for the same. if you have better choice than interspire we can go for that too. (should have more or similar functions like interspire cart) and easy to manage. you should have previous experience in developing templates for shopping cart. currently interspire provides more than 20-30 templates. but we need to manage as per our need. there are two option either you can modify current templates or can create new.