I just finished a new PDF book of traditional Celtic, Fiddle tunes and Old Time tunes for C6th electric steel. You don't hear them on lap steel very often but they work surprisingly well.
Here's Tony Rice's beautiful ending to "Cattle in the Cane" reinterpreted for lap steel. Ending is at 01:37 in Rice's 1983 recording. You could tag this onto a number of tunes in different genres in the keys of A major, A minor, or whatever key your ear tells you works.