Looking for a new commercial HVAC system

I opened a new business- before the coronavirus pandemic- and everything was going great until I had to close my doors.

I only have a few employees, so they were able to find some work in the meantime until we can open back up again.

We were beginning to have issues with our HVAC system before we had to jump ship, though. I would like to have the HVAC issues straightened out before we get back to work next month. I talked to my HVAC provider and they said they’d be willing to install a commercial HVAC system but that they only sell residential HVAC system units. Does anyone know of any commercial HVAC systems for sale? As long as it works, I don’t care if it’s used or from a foreclosure. I would prefer a new commercial HVAC system but if the price is too high I can go for a used one. I’ve never searched for commercial HVAC systems before and don’t even know which HVAC brands are best known for commercial use. My HVAC provider gave me some direction, but they almost exclusively work with residential HVAC systems. I did some research on commercial HVAC systems online but, of course, all of the HVAC brands said that they were the best, so I’m not really sure what to do. Is there an industry standard for commercial HVAC systems? Are the commercial HVAC systems ultimately the same as the residential HVAC systems? If they are, then why is there a distinction between commercial and residential HVAC systems? I could really use a little help if anyone has advice or knowledge about this!
a/c care