A web develop with experience in Interspire Shopping cart

our online site/shop is built on interpire shopping cart. An expert who knows what is required to help with the following fix: 1. Implement a cache for the website to reduce the server load of the site(The site is eating up our server space. 25G is already gone) [login to view URL] minimum order to allow check out at N2000 (orders below specified amount will not check out but will show a notice telling them so) [login to view URL] we only offer intra-city deliveries, we want to change every instance of shipping to Delivery on the check out page. 4. 2 Custom themes for the website Kindly indicate prices for the services. Thanks Please respond with your quote and be convienient with pay after service