WHat kind of racing are you looking to do? Sprints, Ironmans? What kind of courses? Do you think you'll go disc in the rear or just two deep rims, or maybe trispokes? Do you plan on doing any road riding/racing with these?
If you can answer all these questions you'll probably have an answer for yourself.
If you want these for purely tri racing, I've heard a Disc in the back is best and it doesn't really matter if it is a $70 CH Aero cover, a RENN disc(around $400, probably best bang for the buck) or a $1000 Zipp, a disc is a disc, dimples or not. If you plan on doing the Hawaii Ironman, no disc I'm guessing.
Front wheel is debatable between Hed's trispoke and a Zipp 808. Really though, if you're a smaller rider neither of these are great all around options for a front wheel. You want to look in the 40-60 mm rim depth range. There you have an amazing amount of options.