Pieter...
I'll try to narrow it, or at least classify it, a bit for you:
Flatbow, or traditional longbow: this is th Howard Hill type bow... long famous. Smooth, forgiving, and not terribly expensive. Straight or relatively straight grip. A new Hill can be had for around $500 from Hill Archery, and they have made many heavy bows for African use. Only problem might be that some folks don't seem to be able to adjust from shooting recurves to shooting straight grip bows, but these are a great style bow and there are manufactures besides Hill that make them. They can be readily found used. Hills particularly seem to show up in high poundages. I picked up an #80 pounder used last week and am hoping it will arrive today.
Reflex/Delfex Longbows: These are the very popular longbows with gently double curved limbs... many brands/makers to choose from. Black Widow is well known and has built for African use, but is expensive. Some of the smaller custom shops have also. The grip form is usually a sort of gentle locator type, like a semi-recurve grip. Some folks shoot them low wrist like a flatbow, others almost high wrist like a recurve. Check out the used bow pages for many examples. This is probably the most common type of longbow today.
Hybrid longbows: These are straight limb bows, or occasionally R/D types, but with recurve style grips. I tried a couple but didn't care for them, personally. However, lots of folks love them and they apparently make the shift from recurve easier. that was probably my problem... I was trying to go the other way as I had never shot a recurve regularly.
Sorry if I'm telling you stuff you already know, but I thought it might help you to get things into identifiable categories.
Dick in Seattle