Are your keeping the RIO?
If yes, you should follow Rogers advice. I'm at your technical level, but heavier at 210lb. I tried a 139l GO and don't feel like buying one since it is similar in usage to my Kona longboard. And I find that a longboard is better in low wind since it is here very inconsistent. A longboard is better in these conditions since you never need to swim back to shore, and it is much nicer below planning threshold.
I am now using a 115l Starsurfer (similar to Kode Tufskin) that I bought for the kids. At my weight, it is difficult to uphaul, and I'm in fact focusing on waterstarts now. But once running, it is much nicer in the chop when powered on my 6.0. A 115l board for you would be great since it will be quite different from your RIO, while being uphaulable.