I would say no to the Dago Red as a 3rd plane but the World Models P-51 Mustang 40 size is not bad. Personally I didn't find it that hard to go from a tricycle landing gear to a taildragger.

Really you are the only person who knows how well/confident you are when flying. If you feel very comfortable flying your current plane then maybe making the jump wouldn't be so hard. If you are in any way unsure about flying your current plane then hold off for a while.