Combine two wordpress themes for functionality And also create membership.maindomain.com

Basically I have three wordpress themes... [login to view URL], buzzinar, and OptimizePress. I want to use OptimizePress for membership under [login to view URL] and use [login to view URL] as the main theme with a link to membership on menus... Also, want to merge pages functionality from buzzinar to use with the main theme. The pages are already setup but the css style is not correct for the main theme so will have to edit the css style to work properly with the new theme... i.e. the content box from buzzinar sample pages too large for preferred them size, thus will need to resize the content boxes of 9 pages to fit the main frame. Furthermore, would like to have a floating social connect button added to my site. And configuration of a membership script with optimize express. This just about summaries the project... more info on which pages to be customized will be discussed with the winning bidder in details.