Welcome Joe, i hope this thread hasn't put you off this site....
so you want to put a 20B tripple rotor into your 1200 Ute... man i think nit's an awesome idea. i think being able to put a 13B or 12A into a 1200 without too much trouble means that the big brother of these engines shouldn't be much harder.
as you can see there are a few Rotor Dats out there and some guys on this site who have done this type of conversion, my best advice is to ask them a few questions. (maybe a PM would cause less people to get their back up about these things, which is sad in a forum

) but anyway back on topic.....
i would also suggest talking to a local rotor workshop about what they suggest for a reliable running tripple rotor in a different car. i suggest staying with injection and maybe stock turbo.
the only big hurdle will be getting it engineered. because you would be looking at an engine size going from 1.4L to 4.XL i think? i'm not too sure on the size difference but a 13B equals 2.6L.
talk to your RTA and get some info on what would be needed to get it legal and then get to it. keep us interested people up to date....
good luck