If you have two teenagers, boy and girl, it's not likely they'll want to end up in the same bed, or in bed with either of their parents. They'll likely want some privacy, too. I think the minimum for you would be a 1-bedroom unit, bringing along your own air mattress. A 2-bedroom would likely be most comfortable.
As to views, it's not first come, first-served. I booked a trip for two weeks ago in March, on the first day booking was available. I requested an Epcot view and didn't get it. I don't know if that's because there are no 1-bedrooms (which we were in) with that view, or how those things are handled. You can request what you'd like; after that it's up to the vacation gods.
Hope that helps.