Thanks for the info everyone - extremely helpful
I've found a Manfrotto Neotec monopod (685B) to match my Neotec tripod
It's on the heavy side though, so I might get a lightweight one too.
I'm glad to see the prices seem to have dropped since I first looked at getting one
I was really in the dark about monopods, but with increasing interest, so again thank you for your detailed and very helpful descriptions/explanations, much appreciated