Walters doesn't come down to Tennessee. I do have a quote out to Lester pole barns. Oh...I am doing my homework, its all in the details. I don't want to have to put in a door later...better to get it done while the building is getting framed out. I am not going to rush it !
Good thinking. I have seen Lester Bldg ads for years and would presume they are reliable and believe them to be. An internet check should help you in that regard. I'll bet 99.99% of people build the exact same thing in a barn despite all sorts of intentions. There are mostly just low buck and then high buck versions of the same barn. No weird metal colors. Off-white with medium green 3' strip on the bottom and trim look nice. Maybe same green on roof. It won't bleach out. Morton's site has nice color ideas. No earth tones or dark colors.
When you do agree and start...make zero changes or it will really cost you. Keep it simple and nothing funny. You only need a small window because the light draws the bugs. You need a solid, no window man door or perps will have an easier time trying to break in. Sky lights usually leak. That's all the options there are. Read the Morton website for thoughts and color combos. Screws rather than nails in the metal make any (remote odds) leaks and dents easier to fix. An inside wainscoting stops dents. Screen under the ridge vent keeps birds out but sometimes leaks a lttle. Mouse traps in the early winter.
Build bigger that you think you want or you will wish you did later. One or two end doors and one side door 2/3 of the way back fits the most stuff in and a two or maybe one foot overhang with gutters. You get to build the pad and hire it out. If you want concrete, it goes down afterwards and is 4" or 6" in the middle and 4" on the sides or if you bring combines in, 6" all over. Make the floor extra smooth and of a higher psi mix. Epoxy coat it before you move everything in and read my earlier threads on that.
You can put up an insulation drip barrier in the inner roof but it can also actually increase condensation issues later. I have one barn with one and it actually sweats inside on everything in the spring and everything inside is dripping wet in condensation. The barn with no roof insulation is mostly fine and these are both unheated buildings. Ideal is to heat the building as it warms up. Metal barns can sweat with no inside heat during seasonal moisture changes.
Have a "barn christening" when done and if you can score some old beer or cigarette neon lights, it sets off a romantic glow for you and the wife. Your old 4' high stereo speakers sound great in a barn. Build a 30 ft workbench and find my previous threads on that. Put up maybe 12 ceramic ceiling outlets for 300 watt bulbs and use fluorescents over your work area. Make a rolling 4' x 8' metal table with a plywood top skinned in replaceable Formica and mount your vise to it. See my earlier threads on this.
Did I mention I had built a number of barns built over the years? Good luck.
Edit--The lo-buck barns tend to be 10'on center with the posts while the hi-buk versions are 7'6" on center.