I'm not a fan of Redcat because of a lack of parts support. If you break a part, you usually have to wait quite a while for a replacement. There is also little to no aftermarket hop-up parts.
If by Gas you mean nitro Then I personally think the XXL/LST2 and the Savage X SS are two of the best MTs on the market with the XXL/LST2 being my favorite. The only thing I dont like about the XXL is they went front nice threaded aluminum body shocks on the LST2 to plastic ones on the XXL. The XXL has much better and slightly bigger engine though.
The Savage XL is good I think if you dont use the stock motor. There are some other good ones though...Associated MGT is good, A TMAXX can be good if you spend enough money in extra hop ups to increase its durability. You'll have some of that with every kit but the TMAXX takes more than most. Not a big TMAXX fan myself but some people love them.
The Rampage is a 1/5 scale two stroke gas burner. I don't have one but we had a member here that did. He(and I've heard elsewhere) said that the 1/5 Redcat stuff is better quality than their smaller scale nitros.
Do some more research your self though,like I said above I do have one personally.
My mistake...I wasn't aware anyone made a 1/5 scale MT. Anyone else make one? Although IDK that Id want anything bigger than my XXL....damn thing is heavy enough when you have to carry it all the from your favorite bash spot to your truck when it brakes lol.
I haven't broken anything that would keep my 1/5 scale from driving. I just ripped the plastic under tray off of mine when i landed on a rail road track after a wild jump at full throttle. The 5b's are tough buggies.