7 people and all the luggage is going to need a big vehicle.
It's not the
budget option, but in case you didn't know,
RCCL does run a shuttle/bus from MCO. So you *could* take DME back to the airport and then catch the RCCL transportation. It's about the same as the
DCL bus, around $35 per person each way, and you would have to take all your luggage on (under) the bus on DME with you of course. So it's not IMO really the best/easiest/cheapest option, but it IS an option.
We went from a Universal resort and hired FLtours.com to take us there. We happened to take a limo, mainly because DH had never been in one. If we did it again, and if we were packed as heavily as we were that time, we'd hire a big SUV not a limo. Weirdly, limos don't have all that much luggage space in them!