Create 2 Complete websites with ongoing SEO and Management

Hello all. Lets starts with some info about us. We sell artificial flowers, wedding accessories, party items etc. At the moment we have a website based on the Opencart platform. From there we do both retail and wholesale, however we are finding drawbacks to the system. What we want: We intend to do a full rebranding of our company, which will completely separate the retail and wholesale sides. They will both have new names, and new websites (the existing domain will redirect to wholesale only site). We are happy with the new sites being based on the Opencart platform again and just being custom themed and modded. We are a user of Channeladvisor so both sites will need to integrate for stock management via the API. Both sites will need heavy SEO work doing and bringing to the top as quickly as possible (using safe and clean methods only). Wholesale site can be simple but the retail site will require keeping up to date with new banners, offers etc. Existing data can be provided in XML format and you will be responsible for getting everything transferred on to new sites. We only want to work with the best so please ensure you already have an impressive portfolio.