I do live payroll processing, so I have to have a laser printer to print the MICR code on my client's checks.
In addition, if you need to print any bar codes or qr codes, many inkjet printers are not precise enough.
Get laser and make sure it has generic refilled cartridges online to buy. IMO Brother is an excellent brand and can be had very cheaply. They are all very similar. If you want to go ultra fast, you'll pay for that and HP is probably the way to go.
I just purchased a mobile printer / scanner for a few clients I service on-site.