not a whole lot of difference in them.
i got one from repco i think, was like 50$.
only complaint is the chassis on mine isnt the best, and the trigger has broken, so i need to depress the little switch with my finger.
other than that it flashes good.
try and get a smallish one, so you can monouver it into a good spot. mine is fairly chunky (gun type), and sometimes a bit hard to get into a good spot.