Nuhorizons alternatives for Xilinx parts?

I am currently doing work on a small board with a FPGA and DSP. I have been planning to use the Xilinx XC3S1000-4FT256C , but Nuhorizons doesn't seem too interested in selling me 2 for a prototype. Where else could I find these? The Xilinx online store only has parts up to the XC3S400. I have checked digikey, but they are a few years behind on the Xilinx parts.

I may have to consider changing to Altera since Digikey seems to stock them. I really don't want to do this, but if forced by unavailability of parts I will have to.

Darrell Harmon