Stanfield's Superwash Wool is listed as 90% wool 10% nylon.
Nothing mentioned about it being merino, so probably isn't.
It's not itchy - don't know how they do that.
It is hard to find - I usually get it at The Bay.
Stanfields does sell some items online, but not all.
http://www.stanfields.com/
Just noticed they make some FR stuff as well.