Im not an expert on exhaust brakes by any means, but I know they are expencive, but well worth it. I couldnt give you any specific brands to look for, but I have seen and heard of kits that use the valve on the back of the turbo, I guess its a warm up valve in the exhaust? Well anyway This can be used for an "exhaust brake" along side of a warm up deal. The obvious 2 benefits I can tell u are 1) extended brake wear, because of the braking force. 2) faster warm up.
Like I said im not expert, so I couldnt give you any cons to an exhaust brake, Ive only ever heard the good stuff. I have driven a few trucks at different jobs that had them, and I will tell you I love them, (but prefer a compression (jake) brake anyday!)
BCD offers a variety of (I think) good, cheap, Powerstroke stuff. Here is a link to their page, more specifically the BCD brand, Powerstroke stuff, scroll down the page and you will find a kit for $100 bucks! It utilzes the stock exhaust back pressure valve (EBPV)
http://blackclouddiesel.com/Ford/ourfordstuff.htm
Between you and me, after I saw all that stuff that they make for the price, I been lookin at the darkside!!
(but i'll still keep my ol IDI)
Hope this helps ya!