A 4 stroke troll motor would be nice to have..... but

a new battery for that Electric troll motor would be a lot cheaper way to get down to .9 to 1.7 mph for kok's.

Down riggers are also nice to have but as mentioned.........
leadcore and regular old lead weights from 3/8oz up to 3 oz. will get your gear to the fish.

The "Fish Finder" is the #1 unit that you will need to locate and catch kokanee.
anything else is just improvements..............

Good fishing.