Hi Tom,
Thanks for the really good reply there. It's very much an echo of my gut feeling.
I think i'm going to plump for, picking up the domain name, creating the clients site, putting 80% of SEO efforts into the branded site and the other 20% at keeping the exact match on the go as almost a side project, as they will hoover up some clicks based on the search term.
Thanks again for the welcome and the advice, it's much appreciated.
Mark