I think Cabela's is the best source for most stuff.
I like their 7-pocket pants--long and 7" inseam shorts. Also their short sleeved shirts. Their safari jacket is on sale for $49.95, I believe.
Make sure you know the temperature range. I've seen frost in RSA in June and 90 degree temperatures in Zim in September.
Other stuff might include two warm sweaters and, as you were advised, three sets of each type of clothing.
Next time I think I'll wear a set of hunting clothes on the plane.
Footwear? Any good goretex hiking boots. Go to your nearest outdoor store and ask them what they recommend for several hour hikes. I packed a higher pair and wore a lower pair on the plane. Some short tennis shoes doubled as slippers. Socks: The hiking store recomended two layers, some thick ones on the outside and thin ones on the inside. I dispensed with the thick ones.
If you wear shorts, buy a pair of gaiters from the hiking store or--much better--from Long Grass on the Internet.
Clothing should be dark green, not light khaki.
Any non-garish baseball hat works.
A light pair of gloves.
A small flashlight (and a spare).
