Thanks lad's.
Some of the tyres I was thinking about have really stiff sidewalls and what worries me is having to get the tyre off to change an inner tube - so I'm kind of liking the Scouts, as from what I've read it seems you can do that easily enough with three tyre levers. Also, they seem to do okay in hot climates. Even though I've got alloy's and I can run tubeless, I'm fitting inner tubes. Yeah, yeah... I know its overkill, but I'm definitely not going fast and I want to avoid punctures wherever possible.
I actually think I'm maybe asking too much of my tyres and about 8 to 10k seems about average. I've been watching loads of reviews on YouTube and online, and like anything in life, the 50/50 tyres are always a compromise. I think much of my trip will be on tarmac, though not very good tarmac. But I do know that at some stage the tarmac will run out, which is why I can't use my tourance tyres - which I just love. When I did Europe last year I did over 6k miles, and I still managed another 2k after that - but - they do have limitations when the going gets a bit rough, which gives me the willies...
I'm thinking that maybe the best thing to do now is change my tyres in Senegal. Its a half-way point, so I've contacted three places in Dakar to see what tyres in my size they stock. I've also contacted three bike shops in Accra in Ghana, which is my turn-around point. Hopefully I'll have some answer soon.
I'll let you know what I finally fit, and when I fit them I'll post a few pics.