6i25+7i76 + encoder feedback (which card to choose?)

As the title ... I have a 6i25+7i76 and I need an encoder feedback (for closing loop on LCNC after servodrive-close-loop). The encoder signal is given from my servodrive...

What is the better choice of mesa card to do these? I have 4 encoder feedback to use....

regards
Giorgio

The simplest option is probably to add a Mesa 7i85 card. That would add 4 encoder inputs. (plus the one you already have on the 7i76.)