I have both craghoppers kiwi convertibles & north face paramount convertibles & used both in Africa. I generally take both but keep the craghoppers for smart going out & the north face for out & about outdoors stuff. the paramount are quite expensive at around £60 a pair but are very hardwearing, have many useful pockets plus zipped security pocket inside one of the normal pockets, the zip off legs are some of the best I've found - zips marked L & R for when you're putting them on in a hurry or it's dark and side zips at end of leg so can be put on / off over boots. The only down side I have found is they tend to pill a bit on the bum.
I would also recommend the Mountain Hardear canyon shirt - both mens & ladies versions. SPF 30, fast drying, very cool to wear as has large mesh panel at the back & under the arms. Very useful fold out collar that covers your neck from sun and a large chest pocket that'll take passport & the long boarding cards so really useful when flying, plus look smart if you want to try for a free upgrade!
Re some of the bug proof clothing - you can get a wash-in treatment so you can buy the best stuff & still be bugproof. Whilst out there - tabard is very good - the stick for you rather than the spray and the candles for your room / tent.