I have a Presonus D8 into ADAT1

Would I need to replace that with a different ADAT, or is there an  DA converter (via optical?) that would allow me to get 8 more analog outs?

I'm thinking I'd like to use something like this this for my headphone sends, rather than tie up the analog outs on the RME, so I can use them for sidechain thru outboard gear

I've looked at the Aphex 141... but the AES d-Sub....

I am using ADAT2 for SPDIF to a 2 channel pre