Marketpress - Custompress - Gridmarket

Multisite (no buddypress)
Primary purpose is for product sales across all sites.

Marketpress Products..
Require additional taxonomies for our products.

Custompress = add taxonomies for "Products"
Do not display on the product page and are not searchable.

We have no need to add post or other types as everything relates to the products which need to be searchable by a many to one relationship.