old clark half cabin eh! i reckon you'll want atleast a 70hp to push it along, you can rego the boat yourself in QLD i think and the Trailer but needs to be in road worthy condition obviously, bit of elbow grease spit and polish she'll come up alright just check over the hull for any splits or pin hole corrosion areas.
you'll need a 17foot trailer at least i'd reckon with brakes