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.
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Electric heat would cost a fortune for a building that size. Can you get a large propane tank and service? I bought a Milwakee 12v heated coat that makes it a lot nicer working in a cold shop. I would consider painting the back side of whatever plywood/osb you use for the walls and ceiling with some of the anti mold paint.