On reflection "West" Africa is not a great description because the region covers only the sub-Saharan half of Africa's sticky-out western bulge.
It is not only the turbulent politics of the region that has kept West Africa comparatively unknown to many British travellers over the years, but also its French cultural identity and language - don't you wish you'd kept up with those GCSE French lessons at school now?!
As a result, these lists are a little thin. There are not many UK-based operators featuring the region.
Published in 1994, Peter Biddlecombe's tales of travelling through French-Speaking West Africa on business, are more than a little dated now but I loved them and they give a great flavour of the region seen through English eyes. (French Lessons In Africa: Travels with my Briefcase through French Africa)