In reply to Alex the Alex:
Boven is fantastic, I loved the climbing there! We were there for a week in September 2014 and stayed at Tranquilitas campsite as mentioned above, which is a great place. It would definitely be much easier with a car if you're staying there - it was pretty quiet midweek while we were there. The nearby areas have the best easier climbing (<Fr6b).
Alternatively you can stay in the town - is this the hostel you tried?
http://rocrope.com/ These guys gave us useful beta while we were there.
The guidebook is available for download here, if you haven't seen it:
http://www.climbing.co.za/wiki/Waterval_Boven - it has some useful info on logistics.
Another advantage of having a car is that you can go to Kruger for rest days