Here's a couple of places that make the titanium shims, just not sure if they have anything for the akebono calipers yet.
Tibrake Titanium Alloy Brake Shims
Hard Brakes - TiSpeed Titanium Brake Backing Plate Heat Shield Shims
There is also a thread on another forum talking about getting some made for the akebono calipers but not sure if he was successful. Price was $75-$100 per axle.