I can see a prop, just.
But that does not mean that there is a motor fitted. The original boat had a prop, and as such a model of the prop will also be included. The prop in the picture looks very small and could be a scale model prop. If so it will not have a motor. The larger of the two Billings models of the Colin Archer is suitable for RC conversion (says so in the kit) it does not mean that the model was converted for RC. To try and retro fit a static model to RC is a job for an expert.
If it was me.
As the Colin Archer model is offering too many unknowns, and the current seller seems unable to help, I would opt for the Moonbeam as I know it is a working model.
That is not an expert opinion, just my tuppence worth.