After looking around I've decided that BSM mirrors are the best cheap and dirty way to go. The electronics for after market install and reliability are not impressive.
My suggestion is to make your own using diffuse field photoelectric sensors. Of particular interest are the sensors that can not only tell you that there is an object near you, but how far away. It would be possible to have a 3 led segmented gauge that could define how many feet away the object is. These are not that expensive, and if you have electronics knowledge and some time you could easily integrate them into your truck.
There is one thing I wish the 4runners had that helped with driving with blind spots is a 'conversation mirror' (also helped keep an eye on the toddler/baby)...Not sure of all Hondas, but I know the Pilots and CRVs (after 2006) had them.