You need the outboard, controls, wiring, fuel tanks, and a motor steering connector. I would suggest getting the quick disconnect type such as:
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There is a "sweet" spot where the 26m wanders. X-models may behave similar. Low speed is ok, planing is fine, but there is a band in between that requires constant correction.
If you are on an inland lake (Martin, etc), a planing capability would add another dimension to the boat (tubing, wake boarding,etc). My 60 etec pushes my boat at 20 mph with 4 adults and no ballast.
I agree with
@rgranger. You're looking at $10-15k to put new power on (turn-key). You might find used available, but you need to research the history of the motor if you buy used.
Boat will be useable as a sailboat with a small motor, but you'll be missing a key feature of these boats.
If you can, tell us what you're going to have to pay for the boat. Advice is somewhat price contingent.