The Hannibal MT is basically a Dunerunner with MT wheels and a truck body. With that being said, the Dunerunner is a solid 5th scale and can take a beating. Also, I have not heard any complaints of chassis flex in the Dunerunner, which is an issue the Rampage MT has. So it's a solid platform to build an MT off of, in my opinion.
Parts support isn't an issue with either vehicle, if you can't get parts from Exceed, you can get them from Redcat. I've never dealt with Exceed, so I can't comment on the service. I've never had to deal with Redcat support, but they are easy to get a hold of and Rob is on the forum all the time, so that's a big plus.
In the end, it's your money. Buy what you feel is the better deal.