My two cents. Don't do taxidermy except for skins (and don't get the black felt lining no matter what someone tells you). Put an 8x10 photo of each animal on your walls instead.
As for animals. Impala and warthog are inexpensive so I would do both. Kudu and Gemsbok have spectacular horns so I would do those. Hartmann Zebra and Blue Wildebeest for the skins and because they are iconic Africa.
