Wow O.O I'm so happy to see more people doing Watchmen cosplays XD lol Anyways I myself haven't worked with Latex...well except liquid latex. But I think you'll have an easier time working with 4-way stretch vinyl fabric, it's allot easier to work with than latex. It breaths better and has much more elastic to it, so making movement easier, it's also what i've seen allot of people use to make outfits like this one and such.
Like these;
Hope this helped, it's just Latex takes allot and I mean allot of work. The guy who even made it said he had to do so many things to it, like casting, and coming up with new techniques. So if you used 4-way stretch vinyl fabric I think you could get the right look, without the hassle. But if you do it with latex O.O please share your experiences ^_^ I would love to do stuff like that.
^_^ Good luck, can't wait to see it.
Oh you should check out this link, it may help you
http://www.syren.com/t-watchmen.aspx