9D280, thank you for the welcome and the words of advice.
I think that second-hand is def. my preference (I like old things - I have a 50 yr old LR!) particularly as I suspect that boats are like cars the initial purchaser loses money instantly... I do have someone who can maintain / re-build engines if necessary, I guess that you can tell a lot about likely use of o/b by general condition of the boat - some people just look after things!
Thank you for the clarification on the size / seating - makes sense - will just have to see what is around & make a decision on bench v jockey seating etc. The main aim of this is to get some children out on the water to instill a love of boats - so speed / ideal boat etc. can be put to one side for now...
always up for meeting and joining as crew (I have some experience!) a good idea for learning preference...