Racer chiming in here. Pick the one that fits you the best. Part of fit is going to be things like BB drop, HT and ST angle. I don't know those ranges off the top of my head but they're important. cyclezen above seems like he has some advice there. After that? It doesn't really matter. Chose the one that is the cheapest or the one that you like the most, as your budget dictates. I think position on the bike (aero), tight fitting jersey/suit and faster tires/tubes make up most of the speed. And legs. Don't forget that.

Also, a good way to make crit racing safer is to attack constantly. Get in a break. It takes more fitness and training, but as I've aged (Master's 35/45 field SCNCA), this has been my preferred method to win. I don't have the nerves for a big bunch kick any more and I prefer to leave all that behind.