John Riggs' boards are still probably the best that I've seen out there but they're pricey (even more so now, with the current exchange rate) and have to be bought directly from him.
http://www.jonsaintgermain.com/books.htm You'll want to get in quick if you want on though, it sounds like he might be winding down that side of his business
. Eddie Burke's got a nice, cheap and simple idea,
http://www.mreenterprises.co.uk/viewproduct.php?id=2006.
Depending exactly on what you're planning on doing, the idea I published in Murder in Mind might be useful to you, I also might have put something out in Mind Fluff too but I can't remember. I know I was playing around with a lot of different ideas for boards at the time but can't remember if and what I published, I know that I wrote up something but I can't remember if it's in Mind Fluff or its unfinished follow up. I'll have to dig them out and if there's anything in there you're more than welcome to it.