Hi Loopy,
I'm 90kg and paddle the 9'2". It works well for me. I would think the volume of the 8'10" may be a tad low for a 90kg dude, especially if there is any kind of chop around. I'm ok on the 9'2" in small chop (~12 knots). It goes well I reckon in small to large surf in full or hollow waves.
Here is a recent pic of a fairly easy wave in less than perfect conditions. It was a hoot in the absence of a better wave on the day.
DM