Look at horse places they will know someone who can make a saddle bag.
Edit more info.
Ok now that I'm sitting at my computer here's what I've found
There are a number of places that cater to the horse crowd, you can normally get them to build you a set for around 150-500 (or more if you want to spend that much)
But remember these are for horses so you might have to work with them to get the right dimensions.
I've found that the once ridgid boxes will start to get soft and formless if there's a lot of weight carried in them, or if they get really wet often,
That can be solved by making stiffeners inside the bags and a kind of "L" shaped bracket that the bag sits on supporting the weight.
When I was thinking about this style of bag I worked out a way to make a kind of hoop that hooked onto the stock R80ST bag mounts while supporting the bottom of the bag.
As far as I know BMW only offered leather bags as an accessory, those bags had kind of funky proportions, tall, skinny and narrow, more vertical then horizontal.
You had to get a different frame for them.
If you don't mind smaller bags, look toward the retro hipster bicycle culture where there are a lot of options for leather and waxed cotton and leather bags.
On vacation for a spell
squish screwed with this post 12-25-2012 at 04:22 PM