Customized Views for Special Clients

We are considering moving our ecommerce site to WordPress and are looking for a way to give different views of our stores to different users. We have several corporate clients that can only purchase certain products from our company and get specialized pricing. We are looking for a way to make a main website and have a way for those corporate clients to login and see only the products and pricing for them, rather than our entire catalog. Any suggestions on apps or widgets that will help? Our current website is http://www.centuryproductsllc.com but we are looking to improve the site and have multiple sections for special clients…

Additionally, we are looking for a way to give clients access to previous orders so they can potentially place those same orders again.