I think I'm leaning towards Greece and Croatia, probably a 10-13day trip. I've started to look into specific cities in each location. Here are my thoughts on Croatia so far:

1. Fly into Split
2. Split
3. Day trip to Hvar
4. Split
5. Day trip to Vis
6. Split
7. Day trip to Korcula
8. Dubrovnik
9. Dubrovnik
10. Dubrovnik
11. Fly out of Dubrovnik (or head back to Split to fly out)

As for Greece, I still need to look into islands and places I'd like to see around there that are in a small proximity and fairly easy to get to. I know I'd like to go to Athens for a day and Santorini(which I know aren't very close to each other but I at least need to hit these two places) for a couple days. I've heard lots of great things about other islands though. It's been hard to sort through since there are so many. That being said I'd love suggestions on an itinerary/island suggestions in Greece. Thanks again for the help!