Hi Spence,
welcome to the swarm. I saw some action around Smik a few weeks back, wondered what was going on. Good luck with Smik, hope it's a good boat for you and it gets some use. It didn't get much use here.
Only place to buy a complete suitable trolley I know of would be AHPC. If you want to keep cost down and make your own you can buy the Bricky's trolley wheels with plastic centres (wider than wheel barrow) at most bearing supplies, then knock out the bearings and buy alloy tube of closest size to fit in hub and make up your own hull supports or buy them from JK Fibreglass (Vic) or possibly the Fibreglass Factory over there may make them.