For a fun weekend or half week hunt, go to TX. For a 14 day hunt, Africa hands down. Will you be hunting 14 days or be gone from home 14 days? You will eat up almost 4 days in travel just getting there and back. But if you can depart the US Friday evening, and arrive home the Third Sunday after you leave, being gone two complete work weeks.. That makes a nice trip well worth the miserable long flights.
If you book with an outfitter who follows the African tradition of NOT charging arrival and departure days, you should end up buying a 12 day hunt with 13 nights plus arrival and departure partial days. Our first African hunt was a 9 day with Crusader Safaris, Andrew Pringle in the East Cape. I can highly recommend his outfit... Our PH was Mark, there was another PH in camp I really liked as well, Tyson. I specifically asked for a short PH thinking I would have a better chance at keeping up
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This outfit specializes in all free range hunting and operates on several huge concessions with varying terrain and species. Depending upon your desired PG species, with a longer hunt, I would highly recommend an outfitter with similar options and to be able to move around freely and see lots of different country and species.
If your budget allows, you might start out in the Kwazulu Natal area for Nyala, Greater Kudu, Common Reedbuck... Then the Karroo should not be missed for Springbok and Gemsbok with good kudu as well. And I highly recommend adding steenbuck. Watch for opportunity on jackal and even Caracal. Try to get into the mountains for klipspringer and Vaal Rheebok, then move down towards the Coastal side of the mountains to experience the real jungle where there is more rainfall.... Great for bushbuck and lots of others. Finish up in a Baavians at the home base.
Andrew (and many others) will likely give you a deal if you want to hunt 2x1 with your son and share the full experience with one PH... This is what my wife and I did and still took 16 critters in 9 days. If you do this, be sure the PH has a double cab truck... Alternatively if you both want to hunt to the max, book two PH's and have at it.
Depending again on budget and how hard you want to both hunt, with that amount of time, you could get into some more remote country and hunt some DG in a place like Zimbabwe or Mozambique! Make it an adventure to remember... Well it will be either way!