I agree with previus speaker. All of todays existing Racing buggys are great machines and If i were you I would look to where you can get The best support regarding spares and what is the most common modell at your track.
People put too much faith in car itself than to them selves. Beleive me, I have owned every 4wd out there and I am now with Ae. Why? Cuz there spares are cheep and easy to get a hold of. It can handle brutal punishment and The drive train is bullitproof. Ae got The hardest and most durable axles and outdrives of them all. And I run it on exactly the same type of tracks as you. Then an undertray is most valuable
Go with what ever car you choose and stick with it and really put in the time to learn your ride and learn how to drive before you change car again. Took me a lot of cars before I discovered that fact so hope this helps.
To answer your Durango question I say this. On dirt the geardiffs really dig in and helps with the acceleration. I had one and it was easy to set up for bumpy dirt tracks. But so is any any car now a days when I know what to change