I added some of these (see below) to my previous Premier Pontoon. Since your Harris has enclosed rails similar to Premier they should work well.
I used 3M VHB tape to install so there were no screw holes. While they are not cheap they are stainless, made very well and look classy. They fold up nice and stay out of the way when not in use.
http://www.iboats.com/STAINLESS-FOLD...FZRahgodlBEOCQ
Dan