Avoid links as it comes across as spam.

Small world. I was on the team that developed a tracking system for School Buses so I can now write there are many competitors in this area. Depending on your needs you can go with big or small names. No one would choose spireon based on what little detail you posted.

Make your RFQ and get some quotes from others like https://www.google.com/search?q=GPS+Tracking+for+Small+%26+Medium+Fleets

It would be hard to compete now that cellular companies have entered the game.