Hi Rod.
Don't be scared of a bit of length and width (the missus certainly isn't

).
At your weight and your paddling ability, I would stick to something around 7'0 to 7'2. I ride a Simon Anderson Mollusc which is 7'2 x 3 x 21.5 and it has proven itself in largish down south stuff though I am yet to try it in Perth average waves. BTW im 105kg, 6 foot and am a reasonable paddler (ok I am 40). I think that you would find anything smaller frustrating to surf. That's just my opinion so take it for what its worth.