For my money, unless you intend to "branch out" in your fishing methods I see no reason for rod holders. My money would go towards a good Livescope setup.
I went from simply casting, to rod holders & long rods for Pushing jigs and both methods are still in my arsenal. I got a Livescope/93sv setup last year & what few times I did manage to fish, I mostly one pole fished with the Livescope. I will be doing the casting & Pushing methods this year, as well as the one poling w/LS, and will still use the LS system for all those methods.
Knowing what I know now about LS fishing, had I had it prior to getting pole holders, double seats, long rods, & line counter reels ... I may not have invested in those things & just continued casting & one poling with the Livescope system.