Eb,
A friend of mine, Dan Grigg, runs a wine shop near me (
www.museumwines.co.uk). He is an SA wine expert and acts as the sole UK importer for several SA vineyards. Recently won an award as best UK dealer of SA wine. Give him a call and he'll tell you what you need to know.
I had a look at what he offers. Wines that I know are good and good value would include the following:
Raats Chenin
Raats-Mvemve de Compostela (top end)
Complete Stark-Conde range (voted best wine estate in SA a couple of years ago and consistently winning prizes - I know the owners, people that do things right)
If you're into Riesling the Hartenberg is a nice one - you can keep this for quite a few years if stored correctly
As mentioned above Hamilton Russell Chardonnay & Pinot Noir are amount the top in SA (price is about 33% more than what I would pay at the estate so seems reasonable).
I don't rate Lanzerac very highly, they were my neighbours for years so I know them well.
If you can get your hands on a Thelema Merlot Reserve do try it, for me one of the best in SA. The standard Merlot is also good, as is their Cab.
Good quality reds can certainly be cellared, I like to drink good reds at about 8-10 years old but the other day I had a 1994 Stellenzicht Syrah that held up very well (as it should, it beat the Penfolds Grange at the time!). Not saying the others on the site aren't any good, but these I know. Hope it helps