Na a good set of AT's are all you need, most guys I seen on the dirt with the MT's just dig the dirt up throwing it all over the place.
Case in point at the suffolk show on that course, I spent all weekend on Road tyres going around giving chairty rides did not get stuck once, there was loads of these look at my Big MT tyres guys giving it the big un and just digging the course up and getting stuck.... seen it many times on the lanes as well,
I would suggest a good set of recovery points front and rear, some mates incase you get stuck, tow rope. CB as well, great to keep in touch with the rest of the crew.
Get experiance, watch others, listern and learn , then you can make up your own mind to what you need ,