I have a friend with a lift in his barn. It lifts high enough to walk under the vehicle but you don't have to raise it that high. His assembled in pieces and didn't need any sort of hoist to install.
It sounds like your barn is going to be a pole type construction? When I built my shop I wanted a walk up attic. I did a stick built building on a full foundation. To have a pole building with an attic the plan had to be stamped by a PE. No second floor no stamp required. Doing it on a foundation meant I didn't need an engineer involved, a local lumber company just took my plan and put a package together.
On buried steel gas lines we used a product called Denson Tape to wrap lines. It's a grease saturated cloth type product. It's a mess to work with but the stuff lasts forever. We used it in corrosive areas too and when you remove the wrap to cut a line the pipe looks like brand new. I've also seen pre-wrapped gas pipe. It's steel pipe with a thick yellow plastic tape type wrap. It seems like its usually larger pipe like 3" and up but might be available in smaller sizes.