I don't know anyone persay that you could commission this from entirely, but you're probably better off commissioning this in separate parts. Like the leather armor will be done by one person and the sewing by another. As for altering it for a male version I don't think there is much need to since assassin garb tends to be unisex. If you do want to alter it, you can reference the outfit the stalker is wearing when Ezio and Jun encounter him in the ally. He's somewhere around the 10min mark I believe.
For the armor you'll be looking for a spaulder and a vambrace.
That's all I know! Hope this helps a bit!