Well, that settles it then. I'm 5'10" and my Sterlings are 36.5", which means I'll build some Pinhawk fairways to 41.5". Wishon's SL fairways probably won't be released until next summer at the earliest.
Sterling: A Single-Length Iron Story
Do you have a link to the Wishon SL Fairways? I don't see mention of them anywhere.
Tom has mentioned them several times in the comment sections under Sterling irons and fairway wood designs.