Hi and welcome..

You know the saying..'Missed by that much'..

..I sold my old sup board cheap only yesterday to a friend who bought it for his partner to use.
I also live in Vic..Where are you?
You are right about your weight having something to do with which board is right for you...You need to demo a few boards.
You also should look at getting a smaller board for your fiancé if she is half your weight..Plus you could use it for those glassy days..

I now have a Naish 11'6" and a Naish 10'6"..You are welcome to try both and see what you think.
Stand up paddling is a great sport for a partner to participate in..Much better than windsurfing and kitesurfing imo...Your both gunna love it I'm sure.
Yesterday two fiends Nic and Oliver (both met here on this forum) and Nic's partner and her friend and I had a great paddle together down at St Kilda beach.
It was great for me to do it with others for a change..We had a ball..(and I didn't feel like some kind of freak doing it all alone)..We attracted a lot of attention being a group of sup'ers because St Kilda pier is such a busy place.
The north wind came up after lunch..Oliver battled the headwind to get back to his car at Middle Park..and the rest of us did a downwinder down to Elwood beach.
I'm not sure if SHQ have any demo boards or second hand boards for sale call them and ask for Paul..I think RPS has some demo boards that they are keen to sell..You could also try Mordy..they might have something.
I'll send you a PM.
DJ