Many thanks for the tips and information all of you...
Just to let you know, I managed a price of just £500 on the 8hp Yamaha, incl tank, two fuel lines and all the original manuals etc. Feeling quite chuffed with that!
Good to hear it should plane with two adults on board as well! I hoped it would. Thanks for the comment on the Bravo pump as well. I will definitely be purchasing one of those!
I'll let you know how it performs once I've picked up the outboard and had a chance to play with it...