Blank canvas, steel sided 40x60 pole barn. Thoughts on insulating, electrical, heating???

Hey all, long story short, I have been planning a 40x60x14 pole building for some time now.
My builder called me with a surprise opening, and its nearly done.

I am a busy guy, and haven't put much thought into "finishing" it with electrical, insulation, and heat.

Opinions on the following?
Insulation
Spray foam?
Roll bat?
Foam board?

Wall finish
Osb?
Obx?
Plywood ?
Rather not drywall

Electrical
External conduit if I do osb walls?

Heating
There is no gas here
Electrical 220 heaters?
Radiant floor heat? I hear recovery is poor and expensive to install...

Obviously not looking to break the bank...so spray in foam may be out...same with floor heating. Just looking to do this logically and not do things twice...or backwards.

Thanks for the opinions all.
View attachment 1715660321

Looks nice! Black canvas? Can you elaborate? Oh and from everything I've seen with friends shops around here and read on the net, plywood seems to be the best compromise 'tween price and durability.

Oh "BLANK" canvas. Nevermind. I'm stupid.