LINY had it right 231mm, I was close.
They are for an '04 Tundra, and I purchased them already powder-coated from a company called NHT. They rebuild takeoffs and powder-coat them.
The Calipers are $323.08 free shipping, no core charge
This was the cheapest place I could find them, they are also one of the only sites that don't have a core charge. They come in Red, Black, and Yellow.
Red
Black
Yellow
The Brembo Blank rotors were $112.41 each, cross drilled or slotted are $200.00 for a pair (I didn't get the drilled or slotted because I am not convinced that they would help much)
Blanks
Drilled
Slotted
The only other things you need are new pads, shims, and 4 caliper bolts for the Tundra. The calipers come with new clips and pins as well as some ceramlub brake grease. I bought my pads and shims from Toyota. I don't remember exactly how much they were but I would guess around $120.00 with the new bolts. Also the calipers come with a $50.00 core redemption certificate, so you get $50.00 back if you send back the old calipers.
I would say it comes out to around $600.00 when everything is said and done. A little hefty but well worth it in my opinion. Another note, The 191mm calipers are supposed to fit inside the factory 16" wheel. the 231mm will definately not fit in the factory 16" wheel. So unless you want to grind into your factory wheels, you're gonna have to go aftermarket, or spacers.
Here is a write up on the install
http://www.off-road.com/trucks4x4/article/articleDetail.jsp?id=595244&pageID=1