Gidday Anton,
Do you have access to a workshop and tools?
Can you weld - or tack a job together so someone better skilled can finish the job for you?
Basic woodworking skills? [can you drill a hole / cut somewhere near an intended line without leaking too much blood over the job?]
If so, you are doing better than many of us
As you are intending to sail in a car park, I would recommend the "LEFROY MINI" as it is smaller, and better suited to tight areas, as a bonus - it is also easier to transport and store.
Sails, masts and booms do not have to be expensive.
Over the last few years, I have collected loads [literally enough to overload a small truck]
The most I have paid is $15 for an item.
Many came from our local council recycling depot, some from roadside pick-up during the annual council bulk junk collection, a pile of mast sections were donated by a local surf shop - sail maker [remains of damaged gear left behind by customers.]
Even the big bin at one of our local beaches has supplied more than a few sets of gear [albeit a little damaged]
I have had great success with bunging up begging notices on this forum's windsurfing "free stuff" page.
Many windsurfing fanatics seem to have a compulsive "need" to have the latest gear, and often have a collection of so-called "obsolete stuff" that they are willing to either give away or sell for stuff all.
Sometimes, their wife, girlfriend or mum have happily given away the surplus gear "on their behalf" - without telling them
The chassis is all easily available steel tube - salvage yards, council depots, offcuts from local factories or fabricators [or even Bunnings]
Bodywork - recycled plywood packing cases, or ply from Bunnings.
There is a huge variety of bodywork types and styles you can try - simple plywood tray, complex curves, foam and fibreglass, aluminium sheet, IIRC, one of the crew even tried layers of corrugated cardboard with fibreglass and resin!
The most expensive items will most likely be wheels and pulley blocks.
Wheels - do not mess about with the junk at Bunnings or anywhere similar - they fall apart at the most inopportune times and usually in spectacular fashion
Go direct to FALLSHAW, and get their plastic wheelbarrow wheels.
These are light, practically indestructible and good for over 100kph!
Our local Fallshaw distributor gives a substantial discount - when we tell the owner that we are buying for a landyacht.
We ask for a package of 3 x wheels ready to roll - complete with 20mm I.D. high speed bearings and the adaptors needed to fit them to the wheels.
Pulley blocks - my first sets were freebees - salvaged from exercise machines that were being thrown out during an annual council junk collection!
"Proper" marine grade pulley blocks with larger diameter pulleys are better though - "RILEY" are locally made, and very good quality.
Sails - as you intend sailing on bitumen, you have an advantage.
Surfaces like beach sand or grassed ovals can give a lot of drag, while bitumen is much easier to get rolling on.
You can get away with a plain unmodified windsurfing sail - which makes it much easier for a beginner to learn with.
Only drawback with bitumen is it wears out tyres a bit quicker - but as the rear wheels are canted over and wear off centre, you can flip the wheels around every so often and double their life.
My recommendation - base your yacht on the Lefroy mini plans - maybe alter it for a bit more ground clearance [speed bumps in the car park?]
Start looking for any sails, masts and booms you can find locally - bung up a help notice in the windsurfing free stuff section and keep your eyes open.
Half the fun of these landyachts can be in finding the bits to make them!
Keep your bodywork simple to start with - check out Chook's earlier timber bodied landyachts for ideas.
Don't be scared of asking questions - or pointing out anything that is unclear in the various plans.
Paul [AKA "landyacht"] has asked for constructive criticism of the plans so he can update them.
We love these things - and don't mind spreading the love!
stephen
[certifiable scrounger]
