My sister bought a Jeep stroller for her older DD, and it worked GREAT! It is REALLY easy to use, even though the wheels aren't that big. It also folds up very compact, very easily, is lightweight, and I think she got a good deal on it at Costcos or Sam's. Sometimes big strollers can be difficult. If it is small enough that it can slide under the seats (even part way - there is quite a bit of room there) that is a big help. If there is no hope of it fitting under a seat, it might be a pain, but if it is that big...won't packing it be a problem?
Also, I don't know about your stroller, but the more light weight and easy to fold the better. My sister had a jogging stroller that had very heavy wheels. Ugh! You'll have to carry the stroller, plus the kid, plus all the disney goodies, jackets, drinks, etc. on and off the bus. (They make you fold the stroller BEFORE they let you on the bus.)
In a side bar, we saw a lady on our last trip with one of those really expensive Peg-Perego strollers that was all shiny and new. All the moms oohed and aahhed, when she got on the bus, "Nice stroller!" Then everyone tried to help her figure out how to make it fold...we were at the hotel before they had it fully figured out. It was kind of funny. To get off the bus, of course, she had to figure out how to open it again.