Any question answered...

Exposing my mechanical ignorance here.

I have buggered my left Shimano 105 5600 10sp shifter. I'm finding it hard to find somewhere that has individual shifters in stock.

Do I have to replace with exactly the same thing? Would a newer 105 model work like the 5700? Is there an SRAM shifter that would work instead?

http://www.chainreactioncycles.com/Models.aspx?ModelID=13646