I have never seen that size in person, very cool (and odd).
A 245/7
0r16 is slightly taller and a smidge wider, and they are plentiful. As
@javelinadave said, plenty of Taco and 4R take-off wheels and tires are available, and the Taco came with the 245 size.
I would avoid E-rated tires, and even C-rated - go with SL's. There's a huge weight advantage of SL vs E or C, and imho it is noticeable in daily driving; and in ride comfort. And it sounds like SL would be good for you since you don't need the reinforced carcass for 'wheeling. Full disclosure: I run Hankook Dynapro AT Extreme SL in 245/7
5r17 and am super happy, excellent onroad and perfectly fine for the bunny trails I ride.
Also agreed, stick with known reputable brands, you'll have your choice at that price point (mine were $180/ea).