Silver Hill is very good. Highly recommended.
An excellent source - very reasonably priced - that I found on Bid or Buy - the South African equivalent of Ebay - is a gent by the handle Seeds_and_All.
Here is his current listings:
http://www.bidorbuy.co.za/sell...
He has about 3,000 listings.
On BoB you purchase in South African Rands and the current exchange rate is
1 South African Rand equals
0.091 US Dollar
And the prices on B o B are quite reasonable. Most are sold in small lots as small as 1 seed. Shipping costs are quite reasonable. In a recent purchase of 8 varieties totaling 100 seeds, the total costs including shipping was 218.80 Rands - shipping was just 55 Rands.