Wow £8000, you are a lucky man.
It's a lot to play with. You can virtually get any bike you can think of for that.
I would save the money for the trip. Spend it on petrol and

.
I can recommend this bike, Yamaha XTz 750. Go anywhere, reliable, less weight than the gs or ktm, good on the road,cheap too, you can save some money on the intitial purchase and kit the bike out how you want.
I got mine for £500, trip ready for £950. Even if you spent £2000 on a bike, £6000 will get you a really long way.... I travelled in France, Spain, Marocco, Western Sahara and Mauritainia for 3 months for just under £3000 all-in, including buying the bike.
You could always get the Drz to get back into it, then take it around the world.
let us know what you get...