Hello, Sackie, - The wire I used is 6 SWG piano wire and is soldered into the 5/16" brass rod, with this set-up I can easily alter the length of the leg (may need to be a bit shorter). The wire may be a little weak for grass field landings (especially my kind of landings!) but I don't intend to operate off the land - just taxi in and out of the water. Landings on the ground could be risky as the wheel track is so narrow, and the tip floats could easily get torn off.
The cylinders are home-made, originally for a Spitfire some years ago, so I was glad I kept the bits after the Spit. self-destructed. The cyl. diameter is 3/4" and travel about 1-5/8". You could probably get them from Robart, or another manufacturer like Unitracts International in the UK will make them to your spec.
The cyl. mounting points are not strengthened as they are bolted onto the 1/4" ply former. and the end stops on the wheel legs will take any shock loading. The point where the axle tube enters the fuz. is well strengthened on the inside of the fuz. The brass operating arms are attached to the rod by Allen grubscrews, positioned in such a way that they can be tightened/loosened by a very long-handled Allen key when the centre-section is removed, allowing the whole system to be easily removed for maintenance (or repairs!) from the finished model. Can supply you with details of how to make the cyls. if you require them - not difficult if you have a small lathe.