Rod holder back packs?

I'm going to Hawaii in early October - one week in Maui and one week in Kuaui . From previous posts from others going to the Islands, I've gathered that your  fishing kayak options can be limited. I figure I'll have to take what I can get at the tourist / kayak rental places. I need something relatively light and portable that I can either slip over or attach to a kayak seat or somehow clip  to the kayak.
OK has a 2 rod, holder that goes over the seat and Apex has a pack with two rod holders that works with their seats. Has anyone used these? What do you think?  Any Ideas on something I can make that would work on a wide variety of kayaks? Remember it has to be light and portable. With clothes, a couple Telescopic rods, some lures, mask & snorkel and maybe a fishfinder I have to keep my suitcase weight under 50#s. Gotta leave room for souvenirs