Love the skin you're in?

So ... what are people's favourite skins?
I'm asking from the perspective of a first-time, but handy and knowledgeable builder. I'd love to hear about the process that worked for you, pros and cons, costs, and any pitfalls. I'd like to skip the ones that didn't go so well. Process right from bare plywood to finished exterior.
This will be a solid 3-season Canadian camper. Stored inside, but hardy enough to be in the weather if need be. Very wide temperature range. My engineering background has me looking for a durable, attractive, cost-effective solution. I don't want it to be disposable, but I don't want to overkill it. The thunder-egg will be 5 feet wide.
Considered so far:
1. The "rich person's boat finish" approach, with fibreglass and yacht paint. That seemed great until I looked at prices for boat paint and realized they were for a quart, not a gallon.
2. Cheapo wood sealer (thin poly) and aluminium skin. I feel like the aluminium would expand and contract a lot and dent easily with rock chips and such. 5 foot metal is hard to source. Don't love the space-ship look it would give my design. Corrodes easily under some circumstances. Tough to repair.
3. Said wood sealer with some cheaper, but still capable, exterior paint. They are getting better and better, I'm told, but I don't totally believe this approach would be durable enough.
4. Natural wood finish with spar varnish. Surprisingly expensive, and I don't believe my plywood joinery (10 foot from 8 foot using lap joints) will be attractive enough to show off at this level. I know it won't because I already did it with painting in mind.
5. Puckboard. Neat stuff, but way too heavy and scratches easily. Looks like lego with no bumps.
6. Canvas and glue / paint. I somehow feel like this will look like I glued some canvas to a plywood thing. People will walk in a big circle to avoid my trailer at campsites.
I'm asking from the perspective of a first-time, but handy and knowledgeable builder. I'd love to hear about the process that worked for you, pros and cons, costs, and any pitfalls. I'd like to skip the ones that didn't go so well. Process right from bare plywood to finished exterior.
This will be a solid 3-season Canadian camper. Stored inside, but hardy enough to be in the weather if need be. Very wide temperature range. My engineering background has me looking for a durable, attractive, cost-effective solution. I don't want it to be disposable, but I don't want to overkill it. The thunder-egg will be 5 feet wide.
Considered so far:
1. The "rich person's boat finish" approach, with fibreglass and yacht paint. That seemed great until I looked at prices for boat paint and realized they were for a quart, not a gallon.
2. Cheapo wood sealer (thin poly) and aluminium skin. I feel like the aluminium would expand and contract a lot and dent easily with rock chips and such. 5 foot metal is hard to source. Don't love the space-ship look it would give my design. Corrodes easily under some circumstances. Tough to repair.
3. Said wood sealer with some cheaper, but still capable, exterior paint. They are getting better and better, I'm told, but I don't totally believe this approach would be durable enough.
4. Natural wood finish with spar varnish. Surprisingly expensive, and I don't believe my plywood joinery (10 foot from 8 foot using lap joints) will be attractive enough to show off at this level. I know it won't because I already did it with painting in mind.
5. Puckboard. Neat stuff, but way too heavy and scratches easily. Looks like lego with no bumps.
6. Canvas and glue / paint. I somehow feel like this will look like I glued some canvas to a plywood thing. People will walk in a big circle to avoid my trailer at campsites.