I just returned from probably my best trip to Belize ever. I suggest checking out the Pine Ridge Lodge in The Mt Pine Ridge area for your inland trip. LOTS to do in the area and very cool accommodations in your price range ($59/nt summer $75/nt winter). They even have a cabana just filled with hammocks! Check out their website at
www.pineridgelodge.com. I made some great inland connections this trip and can hook you up with really cool things to do (mt biking, dirt biking, rafting, herbal medicine, camping/hiking, you name it - I dound the people who do it! Definitely 3 nights or more if you can manage it.