Kim -

Congratulations on booking your hunt, and for the wisdom of including your wife in the adventure.

If at all possible, consider extending your hunt to 10 days. Initially my wife and I, like you, had booked a 7 day hunt, and the PH convinced us to extend to 10. Seven days is better than nothing, but it will pass in a flash, and when we got to day seven, we were pleased to have a few more days to look forward to. In truth 21 days would be about right.

I am sure the double will work well for buff, but I would advise taking a scoped rifle for plains game. It is not impossible to shoot an impala at 150 yards with a double but, again from my own experience, the light gathering qualities of a scope could mean the difference of making a shot or having to pass it up in the dying light at the end of the day. If a single rifle is all you are able to take, a .375 with a low powered variable scope would prove to be the most versatile.