I have had two Bob trailers. An original one built over 10 years ago which just about survived the Great Divide. Replaced it last year with another as it was so good Easy to use and load, waterproof bag supplied but I use an Ortlieb Rack Pack. With any trailer load it evenly and if it is very heavy put front panniers on to stop the front of the bike pulling up.
If you are going light touring you can fit a pannier rack for a full sus bike which attaches to the seatpost and has no brazons. Not advisable if you are really loading up heavily though as it twists the back of the bike especially if it is a full sus.
If your trip to W Africa is going to be over rough terrain consider the Ibex. A bit heavier but worth it for more comfort.