I took all those species in Namibia a couple of years ago during a two week hunt and would recommend Dirk DeBod as the PH. A .300 H&H would do the job with careful shot placement. I would recommend two different bullets. A Nosler Partition for the leopard and either a 200 grain A-Frame or TSX for everything else. You should be able to accomplish your goals in the same hunting area and 15 days is about right.

Don't know what the current regulations regarding the importation of leopard from Namibia is, so check carefully.