Multiple sites using same data

Hello,

Would be grateful for some guidance of how to best implement the following:

I have several sites NOT all on the same server, the sites are on dedicated servers under my control

I want to display the same data on all sites (or at least parts of it by using different detail pages)
the pages include thumbnail images for the area pages and 6+ plus pics on an individual record page

Only the master site would have admin to create, amend, delete records etc

I already run a third party CMS on one of the sites which I will move over to PowerCMS

Any suggestions as to how you would run lets say 6 sites all using the same data

My other thought is not to use CMS at all and to stick to databases

My one thought is to use Navicat to keep all databases up to date but that does not solve keeping the picture upload file
updated and have powerCMS on all sites to ensure uniformity of file and query structure but still would have to overcome
updating problems

Any thoughts on a manageable solution as to how you guys would implement this would be much appreciated

Thank you - Mel