re: Heating and cooling - mini split

Barb, Ryan is absolutely right.  We've seen how you tackle projects and you have all the of the skills you need, especially if you go the MrCool DIY route.   I would classify everything listed on the steps list above as only basic skills required.  Only area you may need help with is lifting the inside units up to hang them on the bracket.  I predict that once you get an estimate you will find that you will literally save thousands.  

I actually did my own electrical work too, including adding a new subpanel to enable more outlets in my shop.  I had a retired electrician friend show me the ropes and that is really not difficult either.  Frankly, 120V vs. 240V are really not that different from each other.   Scariest part was working inside the main box without turning the power off but even that turned out to be less scary than I thought it would be after my friend showed me the tricks of the trade.   But I understand any hesitance to tackle that yourself.   To save money, you could run the conduit, wire and install the boxes and just have the electrician inspect, correct and connect your work to the panel.  That would save you hundreds at least.  And if there is already a subpanel out there, you can completely turn off the power at the main panel and work safely to add the breakers you need.  

BTW, you said this is pole barn.  Is there insulation?  Is it mostly air tight?  If not, I would concentrate on getting it sealed and insulated.  Even without a minisplit, that alone will improve your comfort out there and save cooling and heating costs after you add the minisplit.