My 1988 90 county has the four individual tip-up seats in the back which I reckon are the best option. You can then, for example, fold up some seats to make space for stuff while still having a seat or two in the back. When I went camping last year, we had one guy sitting nearest the door, with the other seats folded for the camping gear.
You wouldn't get this flexibility with bench seats, plus the individual seat backs are slightly shaped to make the more comfortable. I certainly wouldn't want to put 3 on a bench for more than a few miles.
With no seatbelts in the back (not required for side-facing seats) you could technically put 2 or 3 on a bench. If you do fit belts, you use lap belts only.
While they're not technically as safe as forward-facing seats with 3-point seatbelts, my personal opinion is that there probably isn't much difference in practical terms, plus the forward-facing seats really don't work that well ergonomically with access through the back door. Rear-facing might be an option though...