All good advice. Utility trailer shop, axle and suspension shop, or a regular auto repair shop are all possiblities. Get bids because labor estimates are often all over the map. For reference I think it’s a half day, 3-4 hour job at
Scamp.
Ordering the axle from Scamp ensures it will fit, but it limits your options in terms of manufacturer and specs (weight rating and axle arm start angle, which determines ride height).
Is yours a leading arm (axle arms pointed forward) or trailing arm (arms pointed backward) configuration? 4-lug or 5-lug wheels? Do you already have
brakes or will you be adding them? Do you want to keep the stock ride height (probably a couple of inches higher that what you have now) or raise it for additional ground clearance? Would you be interested in an axle that provides adjustable ride height?