The German lads visit the SAAF's test flight centre fairly regularly. Would be then Tornado's, with the distance probably escorted by a flying fuelstop, which if its looks like a 747 is probably a KC-135. With its larger engines it might be mistaken for a 747 profile, if you miss looking at the wings, fuselage and tail.
(just joking). The other tanker can be a DC-10 derivative, not sure of its military designation. I flew in the Cape area last year with some of the T's around, lovely bird if you like toys. Enjoy!