About the Reconstructionists and South Africa, I did correspond with a Reconstructionist who was complaining about the lack of Christian sci-fi writers. He blamed the premillienial dispensationalists (the Rapture/Antichrist/End of Days crowd) for making Christians believe there would be no long-term future.
I remember reading some stuff he sent me and it featured a spacefaring Afrikaner culture. The actual plot involved some lowlife who seduced a girl and refused to marry her afterward, so her brothers kicked the crap out of him and made him transfer her a bunch of his stuff (if she were rich, potential suitors might not care about her not being a virgin). This seems to indicate some sympathy between the American Reconstructionists and the Boers.
(I used this concept in my Afrikanerverse and depicted an anti-Afrikaner American president forcing some of the more radical Calvinists to register as foreign agents.)
However, the actual numbers of Reconstructionists are tiny even if they do write a lot and have a good Web presence. I think it would be more realistic to have a "South African lobby" dominated by rich and vocal Reconstructionists (with some really brave/zealous/insane ones volunteering to go fight in South Africa a la the "Crippled Eagles" for fought for Rhodesia) much like how the Israeli lobby has a strong premillenial dispensationalist presence.