Our Solo series of creekboats, which until now consisted of the Small, Large and Expedition Solos, are extremely popular and considered by many to be the benchmark for modern creekers. Since the Solos went in production, we had many requests from paddlers who wanted a Medium version. So we listened, and created the boat that completes the Solo series. It has the same trusty design of the other Solos, and the same robust plastic pillar system. It also has all the new outfitting, like the better looking seat pads and backrest, better gripping hippads, more comfortable and stiffer thigh braces, and of course our new powder coated die-forged aluminium alloy handles.

That will depend on what sort of creeking you do mostly - low volume or high?
However, without thinking too deeply on that, I think the Medium will be a perfect fit for you. You seem a bit light for the large (which is really big) and i weigh 70kg and use the medium over the small.

Hope that helps...