The existing engineers and technicians are great. Maybe try some Tib Sun maps adding a dedicated medic class?
Medic has a custom medic repair gun, with a wider spray that heals infantry more efficiently at close range, but has no effect on buildings or vehicles.
Medic also has a First Aid ability where he opens his kit, makes the heal sound, and performs a full heal to target, but it takes some time to recharge. Or, just a full health kit that can be dropped with a recharge.
Medic carries a pistol and tib suit (and smoke grenade?) for daring escapes.
The maps should have some reason warranting the medics, vehicle access is limited due to terrain or tib vines?
Jumpjets and Cyborgs would be so cool. There should be a whole set of maps with the Tiberium Sun units.