Your local authorities may vary, but I'm fairly certain that in most places, boilers that operate above 15 psi (or was it 30?) are classified as 'high-pressure' boilers and have much more complicated building code requirements and will likely make the local fire chief ask you to jump through some serious hoops before they'll sign off on your facility. I'd definitely look into that side of things before going that high pressure.
I also did a little quick and lazy math, and to heat up an 800 gallon stripping load from 25c to 87c at 10% alcohol, and a 300 gallon spirit load from 25c to 87c at 40% alcohol, you'd need to be putting out 1,030,800 appx btus per hour to heat them up in an hour assuming a 10% thermal loss on the way to your equipment. This would be your peak load, so unless you wanted to add mash tuns or other steam powered equipment a 31 BHP steam boiler should get you where you need to go. If this is way off I'd love to know so I can update my sizing calculations.