Seat tracks
my recommendation to you is you start with just putting easy to find materials (2x4...books...etc) down under the seat tracks and if you can move them up 1-2 inches at a time that would be ideal. Keep on adding blocks until you are happy and then do what
@Darter6 and either ask your local machine shop for some scrap for sale or go buy the appropriate size metal bars to make your own brackets.