I get a set of new britpart ones - easy to fit mind you after you work out which way around the plates go that attach it to the tub.
Two bolts each side and there fitted - 1/2 hour job to do.
As for belts - you can either get all that gear that goes with the metal bars behind the seats, and bolts to about every panel in the landy, or do what most people do, and get your local metal works to make up some steal plates , and use then to re-enforce the ally, and just bolt them through the tub.
BTW - make sure you don't need anybody with a licences gained after 1997 to drive it as there limited to 7seats+driver, and they will need a minibus license to drive a 110 with the two rows of seats, and two bench seats in!
Also check with your insurance company (or not if you don't want them to know)