i use Competition Electronics Prochrono Pal. Cost me $100, shipped. You might find one on sale for less.
my one complaint is that while it works perfectly in the sun, if you don't buy the lighting setup, you will not work indoors or even in shade if its not high noon.
I shot the thing last fall, and competition electronics had me ship it to them. Including shipping to and from as well as parts and labor, it cost me $52. and i centered the LCD screen at a downward angle, so the 9mm did its job and went right through the innards and exited the back, destroying A LOT of the inside and both halves of the case. the repair was pretty cheap, all things considered.