For internal flights I would use SAA but the other 2 are the South African budget Ryan Air equivalent, never tried them so can't really comment. The one thing I have heard is you need to book well in advance to get cheap flights. Internal flights in SA are generally not cheap, SAA & Comair (A BA Subsiduary) had a monopoly up until relatively recently.
www.flysaa.com
www.kulula.com
www.flymango.com
As mentioned elsewhere, the main roads are fine but SA is very, very big country
http://www.drivesouthafrica.co.za/di...uth-africa.php
Basically Cape Town is 765km's from the next nearest stadium, unless Ireland get based here (which I doubt as I guess it'll only be the seeds who are "based" in on city") it will be a mission to get from Durban or Jhb/Pretoria down here, it's a 2 hour flight from either city and driving is only a realistic option one way.
That said if we were in PE & Cape Town (A lot of assumptions going on there) then it's a stunning drive, and well worth it.
http://www.southafrica.info/2010/
Is a website well worth checking out. Also I will try to stick an occasional update on here if I get any local news which is likely to be of interest.