Hi
Have a look at this site it gives you a load of info about SA plants not too sure about foxgloves and lupins the other consideration is the climate they have winter and summer growing plants I collect SA bulbs and i have summer growing plants in blooms in the greenhouse
Steve
http://www.plantzafrica.com/

It depends partly on how hot your summers are, there. If they are like mine (40º+ C) you can grow Foxglove as a winter annual by planting the seeds in April. Perennial Lupines would be more problematical. In my experience, they refuse to grow much in the winter, and delay bloom until it's too hot in the summer. Cooler summers near the south coast or at higher elevations will open many more possibilities.