I can't see it being much more difficult to make than any other Batman cowl, and there are plenty of threads on here that detail the process for building cowls.
The most common process that I've seen involves sculpting using clay to create the original, and then making a cast and then creating the finished piece out of urethane rubber.
I've never done it myself, so that's a simplified (and probably not completely correct) version of the process.
Then there's pepakura, which is quite popular and again you'll find plenty of info on this forum on how to do that, in fact there's a whole thread devoted to tutorials and pep files on here somewhere.
It would be really cool to see this batsuit replicated, as it's quite unique and could look really good!
Good luck, I hope I helped a bit :\