I also suggest you try with wors... it's far simpler than biltong, because the spice part has already done for you by the butcher; so simply twist and cut to size, soak in vinegar / hot water for a few minutes and hang. With an extractor and heat source; it's ready in 3 days (slightly wet), or 4 days if you prefer it more dry.
Most butcheries (e.g. Meatworld)... sell their pre-made biltong spice mixes; I find that has always been the most convenient and tasty option for me.
As for the vinegar soak; I disagree with Ben Kruger re soaking the meat cuts in only brown vinegar and of course the duration; my biltong comes out perfect using a cup of either brown or white vinegar, mixed with hot water, just enough to cover the meat. At most I leave the meat and wors in that for a few minutes; and then spice the meat cuts using the store bought biltong spice, and hang it. The wors of course is already spiced, so it's just a matter of the vinegar / water bath and then hanging.
To produce a more softer to tear biltong; I find that either you partially age the meat (let the bacteria and enzymes do their thing) as you would for a good aged steak; or tenderise the meat using a meat tenderiser; the needle blade tenderisers are in my opinion preferable to the mallets because they don't damage the structure, for example:
