Until getting my 23 SE six years ago, I never owned a boat longer than 17'. I had to develop some devious storage techniques to keep from tripping over gear. One of my favorite low-cost techniques for adding rod holders is to find the largest cooler that is reasonably portable and bolt a 3-slot plastic rod holder to the front.
The rod-holder/cooler that I have used for more than a decade is an Igloo 48-qt model (shown in green in the 2nd photo). I use it to bring drinks, food, and other odds and ends to my boat on each trip. Even though I have a rocket launcher on the leaning post of my Parker, I always use the rod holders on the cooler first because they don't block any of the cockpit walking room.
When I purchased my Parker, and had more space for large coolers, I added a 124-qt Igloo tied in across the bow area for dry storage and seating. I bolted two single rod holders side-by-side on the left edge of the cooler.
These rod holders are not sturdy or secure enough for trolling heavy tackle, but if you are just looking for rod storage, give them some thought. They involve no drilling into your boat.