Who makes custom sized BB & granite slabs?

You might be able to find something at Grizzly Industrial.

For BB, try Timbernation.com

I'm not sure what dimensions you need but if there is a restuarant or cookware supply shop in your area check them out. They will usually have butcher block cutting boards and granite or marble slabs. These shops have various sizes and shapes in stock. Possibly could accomadate your requirements.

You can get 1.5" tick beach kitchen top butcher block at Ikea.
You can cut it and stain it the way you want.
Please, check my system under white room.

Here is a link for butcher block in 1 3/8", 1 7/8", 2 3/8" and 2 7/8" thick. Available in a wide variety of widths and lengths. I think they may even cut to dimension on request.

http://www.perfectplank.com/maple_butcher_block_tops.html

Here is where I bought 1 1/2" butcher block for my audio rack. They have an outlet about a mile from my home.

Good luck.

http://www.lumberliquidators.com/home.jsp