So many opinions! :D

I have recently started my teardrop, my version of a 8' Cubby, on which the top will be skinned with aluminum and the sides wood. Now my question is, what are your humble opinions on Cabots Varnish? As I'm sure most of you have, I've spent hours this past week reading on and on here on the forums! How do any of us sleep?!
My brain is rambling back and forth trying to decide on what to use. I have a very tiny budget.
Of course I would love to use epoxy and an epifanes finish, but let's face it, $$$$$. I'm not afraid of having to sand a re-coat every few years if I have to, but with care on making sure everything is sealed, will the Cabots do the job for protecting the wood/leaks?
I plan on my exterior walls being plywood sealed (encapsulated) with exterior paint or something similiar, even henrys asphalt emulsion if it doesn't dry smelly!
And over top of the plywood, my siding being sheathing rated pine beadboard. Something similar to this: http://www.homedepot.com/h_d1/N-5yc1v/R-202089045/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053
Which is what the Varnish would be for.
Thanks to you all ahead of time for your help!
BTW, anybody used these guys? Closest non-box store near me.
http://www.suwaneelumber.com/

Of course I would love to use epoxy and an epifanes finish, but let's face it, $$$$$. I'm not afraid of having to sand a re-coat every few years if I have to, but with care on making sure everything is sealed, will the Cabots do the job for protecting the wood/leaks?
I plan on my exterior walls being plywood sealed (encapsulated) with exterior paint or something similiar, even henrys asphalt emulsion if it doesn't dry smelly!

And over top of the plywood, my siding being sheathing rated pine beadboard. Something similar to this: http://www.homedepot.com/h_d1/N-5yc1v/R-202089045/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053
Which is what the Varnish would be for.

Thanks to you all ahead of time for your help!
BTW, anybody used these guys? Closest non-box store near me.
http://www.suwaneelumber.com/