The second model I linked, the Traxxas Slash, has a very high center to it's chassis. This effectively gives it about twice the ground clearance of your average off road RC. This particular feature would allow the Slash to drive along a corrugated roof if the corrugations were big enough for the Slash's fairly large tires to fit in (if they are small corrugations, you won't need to worry). Beware though, this chassis design also gives the Slash a very high center of gravity, so it's easier to roll over in corners. If you birds it will be up against require a nimble lure that changes direction quickly, then something like the HPI Blitz (the first truck I linked) might be better suited for the job, even with a lower ride height.
Most off road RCs will come with a set of preload clips. These clip around the body of the model's shock absorbers, compressing the spring and raising the ride height. It won't do the handling any favors, but it'll be able to get across longer grass and maybe deal with rough gravel better. Don't put to many of the clips on though, as doing so will make your suspension too hard to compress and the car wont get much grip.
And another thing; RC cars are something it's best not to skimp on. If you want something that'll last and withstand a few years worth of impacts from birds of prey, chances are it'll cost you a pretty penny. The Traxxas Slash and The Hpi Blitz are both such vehicles.
Whatever car you decide on, make sure you get the right kit to go with it! With most, you'll need a battery and a charger, although some come with them in the box. And be sure to read the car's manual and get to know what you're dealing with, even if you don't want to get into the hobby side of things.