I dunno... Have you visited them?
Be aware... ALOT of metal building dealers on the web are just that. dealers.. middlemen....AND many are shady or worse.
Google Maps shows it is just an office, NO warehouse, yard, or manufacturing at that address.
Looking over their website, and considering the above, I would really shy away from that UNLESS you clearly know different.
Don't you have a company that does these around you anywhere that clearly produces their own product?
Here's an example of a long time reputable one in TX area.
Look over their website and get a taste of what they provide... and note many locations do fab work to produce their product.
They don't make every single piece, like girts/purlin stock they buy of course, and beam stock... the steel coil... but they do roll all the sheets in house and make all the trim components to order.
And fab the final beams to plan specs.
Marc
https://www.muellerinc.com/