Rick there is never an obvious question so good on you for asking.

You need to talk to your PH. He will be realistic about the distances he can get you within game. A lot of that will also depend on the area (bush) you hunt in and how much the game has been shot up.

My first safari/cull I used a .308W and fixed 6x42 for shots from 40 metres to 200 metres without issue. The game there is larger than here and so easier IMO to bracket with a scope at 6x. I must admit I did wish for more magnification on more than one occasion.

The second Safarai was with a 9.3x62 with a custom shop Leupold 1-4x20 VX-IIc as I was hunting Kudu and Eland in close cover as my primary species. It never got off 4x. Ranges then were 40 metres to 260 metres. I now have a 4x32 Conquest for that rifle to improve the field of view but use it with Express sights. A 20mm objective on an entry level scope like a Leupold is piss poor in low light.

I used that 9.3x62 with the express sights to take an old cull Impala by stalking within 20metres of her. It took two days of hard stalking to do that. If I did not have the time I would have missed out.

Hunting with open/express sights is uber rewarding and I have stripped the mounts off my 9.3x62 for Camels in open country. It is that much fun. I learnt to shoot with open sights so the transition back to them was not too hard.

For the game you list on a first Safari I would recommend a variable. There are no flys on a 3-9x40 with a plex reticle as long as you are prepared to turn it down. On dusk you have to turn it down to 6x or 4x to make the most of the light transmission. Just buy the best you can afford.

My ultimate scope is my Zeiss Victory 2.5-10 x 42T on my 7x57 with reticle in the 1st focal plane. Great lenses and coatings and you can see things on twilight that are invisible to the naked eye.

I always managed to get a rest. Either on sticks or while kneeling. The thorns and burrs in the bushveldt can be unreal. In the grassveldt I used a bipod on the .308W or went fully prone. If you can't pass up a shot then you will be in trouble off hand.

Practise, practise, practise. It will repay itself in spades.

Edit: All you need is the ability to hit a 6"plate at 200 yards and you will be right with a scope. Hit a 6" plate with open sights at 100 yards and you will collect what you hunt. The peripheral vision with open sights (even a peep or Ghost) is amazing.