Are you familiar with "Superfeet" brand arch supports? They are nice because the do not allow your foot to pronate nearly as much as they might if you had the standard flimsy insole. If you go into almost any running/hicking shop, they should be familiar with them.

I personally use them in all my shoes, even my everyday shoes. I use Salomon XA Pro shoes with Superfeet inserts for running and hiking and i have had great luck with them.

I guess what I am saying is look into Superfeet. They will potentially keep your feet from pronating and keep them in the more neutral position keeping your feet from extending...