I would not do that.
DSM10 is OK for smaller Rebel HOT with 15mm servos and is no way capable of (safely) coping with currents in a Classic.
Also, Rex12 Assist + Cortex -> do you really want 2 gyros ? And Jeti Assist doesnt like turbines very much due to acoustic interference.
Safe bet is to go CB220 set with 2x Rsat and switch of your choice (magnetic or the fancy remote) + 900MHz backup which is exactly that i am going to do with mine.