Hobby Shop Support
Do you have a lhs and what do they stock? Do they stand behind their customers? If they do, I'd look at what they sell. If not, might as well mail order so sky's the limit.
I'm a nitro mt guy to. Several Kyosho USA-1 Nitro Crushers, a Tmaxx, 3 Revos, and a LST. I've never hesitated to put them in mud but electrics??..
Electric rtrs require a relatively costly initial investment in lipos and a compatible charger. You've probably got what you need for nitro, with the possible exception of fresh fuel.
You haven't listed any bad brands. If you're going to race, go with what's popular, electrics or nitro. For mt muddin and bashing, I'd stick with nitro.
Keep in mind that for your stated purpose of bashing and muddin, you'd have to take special care to protect escs and electric motors so as not to overheat them. Shield them to much, not enough airflow. To little, they'll get smothered in mud and overheat anyway. Nitro poses the same problem but I've mudded without issue. I don't know if electrics would be as versatile.