Looks like its 4 meters, but because of the tube color and transom style I don't think it's a searider. Could be a super sport.
No ID plate?
In any case, that's gonna be tons of fun.
You might be able to find a bench seat that'll fit but everyone on here will try to convince you to ditch the steering wheel and controls up front and put in a jockey seat console. It's much much better, you have a better vantage point, stay in control of the boat, and stay inside the boat in heavy weather much better as well!