Both great fights. I prefer the Gus fight simply because I don't know how it'll go. I expect Rumble to KO Glover. I see Gus outstriking Glover and defending any takedown attempts, but I don't know whether he can finish him, and I can't visualize the fight well in my mind,.
As for what fight should be made, it depends on what happens with Jones/OSP, and also when everybody involved wants to fight again, from the winner of that fight, to DC, Rumble, Gus, and Glover.