You will be just fine...it's amazing how little you feel on the boat. Take some dramamine just in case, but I wouldn't give it a second thought. It will be a great time!
You can buy these wristband things and I think they work wonders. I have been told it's all in my head, but if that's what it takes, oh well! I have been on several cruises, sometimes i need them sometimes I don't, but most ships sell them. I think it is going to depend on the weather/sea conditions at the time.
anway, I think a cruise would be perfect. DF and I were debating between Disneyland (we've never been and are dying to) or a cruise (Carnival). Then FMIL asked if we would like a timeshare booked in Hawaii and our flights covered!? Ah, HELLO!? Tough choice? Hawaii it is for us. We are going to Oahu and Kauai! I'm super excited.
I think both of your choices sound wonderful, but to be honest, it sounds like you are leaning towards the cruise and disney. Go with your gut and do it!
DF and I are doing a 2 wk disneymoon in October - 1 wk at WDW and then 1 wk on DCL and we couldn't be happier! He wanted to do something different and I always wanted a full Disney honeymoon - so it is a great compromise!