Hi Jam can't tell you anything about the Starboard or Imagine but my wife and I have owned both the NSP 11 x 31 and 10'2 x 32. I am the same weight as you, new to SUP but old prone surfer. The 10'2 does everything OK and nothing well, ok in surf but doesn't paddle straight even with the fin pushed right back. Too heavy for my wife. The 11' is good on flat water for my size - but I couldn't turn it in the surf - it was a total tanker, not very stable in white water either. But you don't want to surf. So if you you want a good cruiser for flat water, stable and aren't worried about surf then the 11' NSP might be OK. We just got a couple of Naish Manas to play in the surf, NSPs are up for sale