P.S. I'm not sure if Johann Potgieter is in SA at the moment but Chris Nixon is involved down there as well and you can get hold of him on 084 7777 802 or send him email at firstname.lastname@example.org for more info.
There is quite alot of DH around Cape Town as far as I know so you should be fine if you don't mind switching over from freeride. Over the last 2 years, part availability has shrunk by scary amounts, a combination of the whole credit crunch deal and Chain reaction cycles has put alot of importers out of business, Marzocchi being one of them. Mongoose continues to import well priced bikes and Kona has started following in their footsteps and obviously Morewood make a hell of a bike. I know Commencal and Santa Cruz are(or atleast used to be last year) available. Shimano and Sram are very popular along with Rock Shox. Other brands like Formula and many others are available although they are normally only available on request. Its definately easier to buy a complete, but if you insist on building up a bike to your spec, do your shopping on chainreactiocycles.com, they smoke local prices by up to 40% sometimes.
Hi John, freeride is pretty much non existent in SA apart from the freeride comp at the Dirtopia festival but even that seems to be fading. Downhill is huge up here in Natal(relatively speaking) and its growing every year. Although the cape definately used to be the dominating force in SA it seems to have died off a bit unfortunately, natal took 7 of the top 10 places at SA champs this year. But the Cape just got new sponsorship for their provincial series and seems to be back on track.