Dinokeng is closest to Johannesburg, but I know next to nothing about it, or the lodges there.

Welgevonden is also doable on a Friday afternoon, plenty of lodges to choose from.

If you can only fly in the afternoon, KMIA (MQP) at Primkop near Nelspruit (Mbombela) is probably your only option. Most lodges are several hours by road from there, though, except for Bongani Montain Lodge in Mthethomusha.

Johan