Not for link juice, no as the sites are new and have low or no page rank. The sites were originally created because they sell different products and if I added the products all to one site, it would make the amount of products on that site hard to browse through "who wants to look through 20 pages to find one pair?". The sites were created to help my visitors. The backlinks were there to help visitors go from one site to the other. If PR is transferred, this is only a plus, and to be honest yes increasing my backlinks was also in mind as mine were dropping off.
My linking scheme is used by many large corporations. Microsoft's main site lists all the products, then goes out and has smaller sites which are product specific. I tried to replicate that. Candlelight carries products from one manufacturer and selected items from the other two sites. The other two sites are specific toward manufacturer and product. This also has worked out for my competition who is ranked #1 (ie Dimoutgifts.com is linked to Dimout.com and Dimoutshoes.com).

Artificially inflate my PR ranking...would it be different if each of these sites were owned by someone else? I can change the registrant, I can change the template. But that is wrong. My goal is to help my visitors first. But yes I keep backlinks in the back of my mind.

Would you suggest instead of having a link from the bottom of every page, only have one or two links from specific pages? Would this be better? Or is using the same template killing me?