If a narrowboat would fit into a suitcase - whilton would be on Peckham Market alongside Del !
Do your investigations thoroughly - whilton do have some good boats but they have also been known to lie about things - particularly the ownership of the boat.
They have sold several (a small number greater than 1 and less than 4) that have sunk on their way to their new moorings.
As Jen says - before buying a boat that you intend to rent out, read up on the laws and C&RTs requirements, eg you will need to have a boat safety certificate to a higher standard that a 'private' boat, you will need a commercial licence and commercial insurance. You will be classed as a 'landlord' and will need to have the boat checked and issued with a 'landlords gas and electical' certificate.
Then there are conditions about having a permanent mooring, waste disposal facilities (rubbish and toilet emptying) etc etc.