wet suit question - camaro brand/F wearing M suit

Hi
New to the boards, doing 3rd tri (IronGirl) this July.  Not sure if I will need a wet suit for the race.  They say avg water temps are right around the cutoff - low to mid 70's. This is the first time IronGirl is at this location, so not prior experience.  However, there is an open water swim coming up in a few weeks (same distance, same lake) that I would like to do to practice and know I will need a suit for that, plus there is another tri I am considering in late Sept that I would definitely need a suit for as well.  I found a deal on a Camaro swim shorty - usually around $160, for $80.  But I am too big for the remaining women's sizes.  Can I use a men's?  I asked the online chat store rep but he had no clue.  He say I could buy and try and return if it doesn't fit, but will I know just by trying it on on land without swimming in it if it fits or not??  Also, the range for a small is 5ft6in - 5ft8in, 141-154 lbs, and 36 in chest.  A med is 5ft9 to 5ft11.  I am about 5ft6 1/2 or 5ft7 and around 155 pounds with a 36DD.  Do you think a small would work?  I am worried the med will be too long, but worried that I am right on the top of the range for a small, and even though my chest circumference is 36 inches, my DD's add a bit more than a typical 36in chested male would have.  I could rent for $40 something but would love to buy this one at $80 if it would work as I plan on doing more tris in the future and this seems like a great deal.

Thanks
J

ETA Here is a link to the suit if anyone has any experience with it.
http://www.scuba.com/scuba-gear-598/056906/Camaro-3-2mm-Swim-Skin-Sleeveless-Shorty.html

Edited by fourUNDERfour 2009-06-01 2:18 PM