A guy I know just started using the snowboard inserts, stainless steel and only 7mm tall so they should fit in just about any board; they look like the best solution.
I also have gotten brass inserts, similar to what's inside the chinook 3-post inserts available from fiberglasssupply.com but without the clunky plastic and also the bottom is capped so you do not have to worry about the screws being too long.
With the chinook inserts they are 7/8" tall so you have to grind them down just to get them to fit in a 3/4" thick board, then the bottom is no longer capped so they are not so good.
The brass inserts are from SW Anderson Company http://www.swaco.com
The product is called "Dodge Ultramold". Fill them with a bit of silicone selant prior to laminating and it comes out real easy later (use a drill bit to scoop it out).