Namibia then neighbouring countries would be my choice, great and generally peaceful places. You can even put your vehicle on a roro ferry that goes to Walvis Bay from the UK, if you're renting a 4wd campermfor 4 weeks or more it can be cheaper. All those German overland trucks didn't all get there the hard way.
If I still can't go to Mongolia next year it's one of our options.
If I still can't go to Mongolia next year it's one of our options.