Yes indeed, the Cerberus and the Charon are both equipped with an EMH Mk II (this is the EMH that has the unfortunate programming that makes it look like Andy Dick

) Pending the arrival of Cerberus' medical staff, the EMH is available if necessary... I had imagined, though, that there might be some SB10 Medical personnel aboard in the interim, as well - running diagnostics, stocking the med labs and sickbay, tending to those injuries/illnesses that might result from any of the numerous tasks that are being done in prep for the Cerberus' launch, etc... Feel free to proceed as you see fit (either 'temporary medical staff' or EMH) should you need to visit the infirmary.
And, that was me, DM, that had mentioned something about picking up a Romulan NPC... if you have some input re: Talon and Sienae, feel free to PM that my way... don't want to go a different direction with the 'relationship' that the two might have if you've already got something congealing.