I have a Beta Chrony by Shooting Chrony. It works well but I wish it held more shots. It holds 60 shots - 6 strings of 10 rounds.
Whatever you decide upon be sure to get a sturdy tripod - sturdy meaning it has some weight to it. A Bogen 3001 or something comparable is an excellent choice. I see people use light-weight tripods (IE "Slik") which may be easy to carry but once any wind blows their chrony gets knocked right over (those screens are very good at catching wind!).