I would go for a NRS frame for the only reason that their oar towers can be adjusted to add 4-5 inches of width to your frame rails. All the other stock options, AAA, rowframe, DRE etc, are a bit narrow (AAA is the narrowest) this isn't a big deal on larger boats, but on a 5 foot wide boat, it is significant. you can only run 7.5 ish oars if you don't figure out something that makes the oarlocks wider. I did a custom thing, and use 8.25' oars. whatever strength difference there is between 1.5 and 1.25" pipe is negligible on such a small boat (never really loaded down)
Another thing to think about is if you have it set up like I do in the second pic for two folks, if you want to solo row, you have to be able to reconfigure the frame (basically swapping the footbar for the seat bar) so you are sitting centered in the boat. other wise, you are filling coolers with water etc to keep you from doing back flips. NRS will do this as will 'fitting frames" like i have but frames with fancy bent corners likely will not because the front and rear bends lock you into only one design. u can't remove the seat bar, and if you could (AAA) it is too short to become the center bar due to the width taken up by the bent pieces.
I had a trib 9.5 which I then traded up for a Hyside Mini Max and went thru all this with both boats. below is the oar towers I have for the mini. Rowframe made the tees, and AAA makes the tower (rotated 180 degrees from how they set it up for maximum width).
Enjoy the mini. Just R2'd browns including twin falls and seidels this weekend. the mini charged the meat on everything with no flips or issues of any kind. Can't imagine wanting to take the 13.5 footer out anytime soon.