My friend who moved to Florida, built one like this. On the edges he had anchor bolts installed when pad was poured. Connected the building to the pad via chain. He also looked around at several that were already erected, and was not satisfied with the end with the doors. He did get the rear enclosure, but built his own front with a custom 16' roll up door.
When you pour the pad, go ahead and incorporate a drain for a shower and toilet. Cover it, so after inspection you can tie into your septic system. Do the same with the water supply. Just makes inspection less painful.
Heating the building is painful on the pocket. But a simple wood stove works pretty good. You might also want to talk to Fishunts dad, he upgrades regular oil furnace burners to allow you to burn used motor oil, which is good, if you can get a good supply set up. You would think that it will be an oven in the summer, but, if you have a attic type fan on one end, sucking the air through, it isn't too bad, but you do need one that moves a lot of air.
When you start building it, incorporate everyone you know, and find some scaffolding, and several good cordless drills. Don't tighten any of the bolts completely to allow you to align the building. Of course, it comes with a video, and it works pretty good.