I have a Woodmizer LT15 bandsaw mill- 15hp gas motor, one extension so can cut logs a bit over 16 foot. No commercial use, just a hobbyist, cut enough red and white oak last year to frame and roof a 24X24 shed for my tractor. I'm lucky and have a Bobcat with a grapple to move logs on to the mill, then use a cant hook most of the time to turn the log.
I boughty mine about 18 months ago, have just started using some of the 5/4 lumber I've cut (oak) to build some small projects after it has air dryed. It's down to about 10% moisture- may try to build a solar kiln this spring- whoops, it's almost spring so better get with it. Would like to have the moisture content a bit lower but what I've made so far has stayed together- would also like to get the temperature of the wood up for a bit to ensure any bugs are dead.
A lot of fun (not sure I'd want to do this for a living!) and great excercise and sometimes a great surprise when you open up a log- sometimes good, sometimes not so good.
What are you looking to do with the wood you cut, fine woodworking, construction, resale?
Good luck with your research.