Hi Blacks
Regardless where you go, your 1st trip to Africa will in many ways be the recce for your 2nd trip, and believe me you will go back.
I hunted Limpopo last year for many of the species you are after and had a very good trip. It is a good area for Kudu, Nyala, Gemsbok & Warties. It is all high fence hunting. You'll start to notice it as soon as you leave Jo'Burg. Don't get hung up about it , that's just the way SA is. The hunting can still be hard. The bush in Limpopo is thick and you travel big distances so spot & stalk is how it's done & you'll spend a lot of time in a vehicle just to cover the ground.

Determine what time of year you want to go. May -June you catch the rut but you'll beat the rush of hunters to a degree & might get better animals...the penalty this time of year is the bush is thicker having not dropped it's foliage. July thru October it thins out making for easier hunting but likely longer shots.

Be sure of what you want to hunt but add a couple of "maybe" animals in case an irresistable opportunity arises. . Also some outfitters will quote you for representative animals but if you knock something above average or in record book inches you'll pay extra for every inch. That's fine but be sure in your own mind that when that massive 58 inch Kudu steps out you might be looking at $27-$2800 instead of the $16 or $1700 quoted.(Shoot it...you can sell the car when you get home).

Whoever you contact over there, make it clear how you want to hunt. The ethics you hunt by in Oz may not be totally appropriate in SA.
Go for min 10 days hunting....you'll have a list of 6-7 animals so allow 1 animal a day (maybe) and 1-2 days where you get nothing.
Most operators offer excellent accomodation & will spoil you rotten.They are terrific people but do your home work & check references.
Your outfitter will likely be able to help organise other parts of your trip (say Vic Falls or Kruger). Don't be scared to ask... you might be surprised what they will do for you.

I'm waffling on but happy to send you a PM.

Cheers

Jon