I'll echo that Hygiena, Neogen/3m, and Charm are very popular in the states. Just keep in mind that ATP testing systems can be a little expensive but can come with software packages that can trend data and provide reports. These can be helpful if used properly. Many of these companies have sales reps that are more than happy to tell you everything about their system, and set up pricing for your company because you'll likely need a steady supply of swabs.
When purchasing these meters I would personally avoid simply buying a meter and swabs, the support provided by the company can be helpful in learning the software and keeping yourself stocked. Buying a meter on ebay could still cost you thousands for a totally unsupported system you end up not being able to use.