I pulled up your address (it's listed on your profile), and it seems like your company does something with hemp and seeds.
1. Do you have any applications (payroll? ERP? Accounting?) that uses Windows and you can't convert over to Mac? If yes, I recommend getting a Mac mini Intel (NOT M1) and install Windows on it, or using Dell.
2. If you do not have any applications that uses Windows, do you have any type of advance security requirements to maintain regulations? If no, then get a Mac mini M1.
3. Does your company have employees that use three or more monitors at once? If no, get a Mac mini M1.
4. Does your company have laptops? I recommend replacing them with MacBook Airs M1 IF your employees use one external monitor. If your employees use two monitors, then you'll have to get a MacBook Pro.
What about Ram? You'll be fine with 8GBs. Ten year old business class Dells usually have 4 GB of Ram, and Macs are very efficient with Ram.
What about Hard drive space? A good rule of thumb is to take whatever your current hard drive space is, and double it. I think your Dells probably has 128GB hard drives, correct? If so, get the Macs/Macbooks with 256GB.
It looks like your company is small, however I recommend contacting Apple for any potential discounts for buying in bulk.
OTHER OPTIONS:
1. iMacs. I do not recommend iMacs if you already have working keyboards, mice, and monitors. It's impossible to use an iMac as an external monitor, and if the iMac display fails, you'll have to replace the entire unit.
2. Macbook Pros (if you don't need two or more monitors). Macbook pros are great, but they are more expensive. An MacBook Air M1 would serve your purpose just fine.
3. Mac Studio. Mac Studios are great machines, very powerful, but very expensive. It's overkill for your needs.
4. Mac Pro. These are upgradable machines, but they are extremely expensive ($5K and higher for each one), and uses Intel chips. They won't be supported for too much longer either.