I've used EZ Clip fittings as well for custom stuff. The fittings are steel (i.e. easier to weld) Check out Vintage Air for the basics and Hose Warehouse for the oddball stuff. HW has alot of neat stuff that will save you from having to make fittings.
https://www.vintageair.com/hose-kits...at2=E-Z%20Clip
https://hosewarehouse.com/field-spec...e-and-fittings