FAVORITE SUPPLIERS & DESIGNS: Greenhouse, hoophouse, tunnel, etc

Farmer/Gardener FEEDBACK please! On greenhouses, hoophouses, tunnels, etc:

If buying new, who is your go-to supplier?

If buying used, where is your go-to marketplace?

If diy build, what are your go-to designs/materials?

Any notable pros and cons?

Thanks friends!

(Pictured here, a lovely house rocking out right now with winter greens at Bauernbach Farmstead in Halifax, PA 👨‍🌾)