Welcome to the 'breeze, Murraymeg!

Bigger boards are not my specialty but two thoughts crossed my mind.

Do you run into many hard objects on the river? If so you could look at an inflatable.

Also, anything that size would float you without any issues, but many of the guidelines you read are aimed at salt water. You are less buoyant in fresh water.

What were you renting? What size suited you the most? What did you have most fun on? That would be my starting point.

And this site has a buy & sell section so you could take a look at what is available. I am not familiar with the brands you mentioned, but anything 32" or wider and longer than 10' long should be fine at your height and weight and experience.

Hi murraymeg
there are 3 different category's in buying a board.
flat water boards or race
wave boards
allrounders .
i have a few friends that have the Halos you mentioned .they are quite good paddlers .one has the 10.6 the other 10'.the 10' halo has 172 litre which would be plenty foam under foot for your 60 kgs .the 10.6 has 190 to memory .other boards ,to mention a few 10.2 JP 10.6 naish Nalu ,fanatic 10'.naish GS 11'nalu.
they are more expensive but at least all the bolts don't rust and you don't have as much deck cave in .
buy and sell have a great selection if you don't want to pay the new price ..get a carbon paddle too not alloy .then you don't have to wash them plus alloy sucks .
the Halos 10' and 10.6 are all rounders .pretty sure ,both are close to 32 .
happy hunting .

Do you paddle with friends, if its about speed and distance pick a board that glides, if its about cruising and talking pick a wider stable board, if its about learning to progress to small surf get a all rounder board, I'm a fan of Fantic Allwaves (or be prepared to get another board down the track)
Also you need to think about how it handles out of the water, or more to the point can you handle it, carry it, transport it, store it at home. On windy days big boards can be hard to carry.

A mate of mine got a 9.2 sup as he wanted to be able to stand it upright in his garage with ceiling height of 9.4

I recently picked up a 10'6 sunova style and very happy with it I am 168cm and 78kg
I tried several different boards but this stood out as an all rounder
it cruises nicely on flat water particularly if I stand a little further forward and for a rookie in the surf is stable enough but I can see it has plenty of room for me to improve my surfing
incredibly light and easy to handle
give one a try before making your decision if you are in Sydney the guys at Balmoral Boards were great