Great central Namibian list and absolutely achievable. Should you go to the Caprivi (at much greater cost) you can likely add free range sable, lechwe (very limited quota), waterbuck, and of course buffalo, croc, hippo, and elephant. I should also note Namibia is one of the very best destinations for leopard.Kudu, Gemsbok, Red Hartebeest, Mountain Zebra, Springbok and Warthog (with a Steenbok thrown in) would be my Namibia Classics.
As several others have implied, I don't believe there is a "best" outfitter. So much in African hunting is about the rapport you develop with your guy. I can easily tick off nearly a dozen outfitters who will do a tremendous job. I have personally hunted with Nick Nolte, Dirk de Bod, and Jamy Traut and can recommend them without hesitation. But as I say, there are many more excellent choices.