Need help to find a good place as close as possible to Johannesburg. I travel there frequently and often have 2-4 days for hunting availible. Suggestions please?

Try Jaco Human who posts here, he's a stand up guy, delivers what he promises and doesn't BS. You'll find him by using the search function.

jo, I did a long weekend hunt with Jaco Human about a year and half ago. There is a thread under the hunting reports you can view. It was near Polokwane, not Johannesburg, but it worked out OK. There are airplanes to destinations such as Polokwane and Hoedspruit so one doesn't necessarily need to spend a lot of time in transit to the hunting area.

Two years ago I spent 4 days of a two week hunt at Mogale's Gate near Joburg with Angus Brown Safaris. About 2 hours from the airport. Game selection may vary over time but I got Black Wildebeest, 2 Springbok, Eland, Red Hartebeest, Gemsbok. All very respectable to above average specimins. My report is posted from the trip. Other species were available.
They have a website and Nick, the son-in-law was a fine PH and loves the on foot spot-and-stalk hunt. It was a terrific time.

PM sent !

Thanks Steve and William, I appreciate your posts.