Hi there,
I am not sure what the hull is, are you sure it is 6' and not 51" or so? Guessing might be an early warehousehobbies hull or similar, but the clue is in the D9 on the side, I am guessing it has been raced / registered with OMRA at some time in it's life, and if you get hold of them through their website it will be pretty easy to track down previous owner who has owned it who will tell you exactly what it is.
However, and to answer one of your other questions, lookoing at the transom it has been previously rigged for surface drive hardware, so you need a rudder, surface drive strut and maybe trim tabs - get them later if needed.
As to engine, it is likely it has had a two stroke strimmer or similar motor in at some time in life, I'd advise ytou go a bit more modern and look out for a second hand (or new - not knowing your budget on this) Zenoah 26cc motor and pipe.
That will be enough to get it moving well.
Would be nice to see it restored and running again.
Glenn