Keith: Take some time and make a list of everything you want in the shop. Then play the paperdoll game, (unless you do Autocad type work), with scale drawings of the floorplan and all your tools and the like, and then figure out a workable layout that will do what you want. Don't forget to give yourself some blank floor space too. Once you have a plan, go lay it out on the dirt full scale and I mean everything....walls, tools benches ect. Massage the plan til it works for you, then start looking at buildings. It's easier to cut down items on the plan, rather than adding once you start building.
As to building types...well, I'm going with standard steel I-beam construction since we are planning to have an overhead monorail in the hangar and we need the height for one of our aircraft anyway. Pole barn type construction is fine for shop buildings, but when youi start to get to door openings much over 16' wide, structural requirements and material costs for the framing and supports climb rapidly. High wind or snow load areas compound the design nees too. I would suggest not going with the super deep corrugation Quonset style buildings if at all possitble. They pose some unique foundation requirements unless you go with the very costly attach rails.
If you are somewhere that has required codes, you will probably have to have stamped drawings, and required inspections, so run all of that down before you settle on a building type. A wrong selection or missed requirement could cost you big dollars here.
Current material costs are all over the place, and shipping costs have to be factored in when you order a building from somewhere outside your local area. I can get a 40'x60'x16' stock buiding local for somewhere between 15 and 19K$. Concrete flat work is about 4$ a square foot.
Look around your local area and see what types of buildings are up and how they've held up to local conditions. Above all. find what will do the job for you, do it efficiently and won't kill your budget. Also, don't forget to factor in your costs for lights, air systems, water and any other systems needs that you can think of.