All CompactLogix controllers that have network ports support produced/consumed tags. Take another look at your configurations; a lot of folks don't know how to select a Producer controller that's a lot newer than the Consumer, but it's pretty straightforward.
In general I think you can wire an ordinary 1756-OB16 to an ordinary DC input directly, as long as they share the same DC common. It's the Diagnostic modules that tend to have more "leakage" than the Input modules can ignore.