Hi indo tubes,Iam like you ,new to SUPing ,I asked the same questions as you have,I wanted a all round board,I went with the Naish 11.4.It's great for flat water,after a month I started hitting the surf on those small and bigger fat crappy day's and it surfs like a longboard.It's great,when the surfs crap it gives me another option. By the sound of things your about the same weight as I am.
As the guy's are saying,go bigger,I've surfed all my life and tried the Naish 9.6,just to hard to start on

,so I am wrapped I went with the 11.4

Down the track I might go for a PSH 10.6 wide,I think it would surf really well for a bigger guy

that's my 2cents
mac