I have tried Tiemens and they are very helpful, but they didn't have the GS bullets I was looking for and quoted 4 months+ for delivery due to manufacturing problems in SA. It is worth sending them an email to check if they have stock of the bullets you're looking for. They did mention that they were setting up a manufacturing plant in Europe but I'm not sure of the progress on this.
I have also tried the Swedish distributor to no avail.
There are bullets available in SA(Limited availability) but I have already burned my fingers by trying to get them mailed to me - DHL decided to confiscate them.
There doesn't seem to be any easy way to get hold of them unless you're going on a trip to SA or USA, or if Tiemens has stock.