You're going to need more than 2 days at disney to see everything. How fancy are you wanting to go? You can stay at the Swan and Dolphin resort which is NIIIICE, a little cheaper is the caribbean resort which is pretty nice too. Look on ebay for a 3-5 day hopper passes to save you $$ instead of buying at the parks. This is what we did the last time we went and saved about 50%. You could spend the entire week at disney, they have 3 huge ass water parks now, one even has the nations largest wave pool.
I've been to Cocoa beach but it's been so long I can't give an accurate review. I just remember the beach was nice but the ocean was ROUGH as hell. There is also the Kennedy space center to check out if you go there. You could go west and hit clearwater beach on the gulf side which is just north of Tampa.