There's endless option... but in the end, I don't think they will go with anything too much out of the ordinary. After all, it does take some time redesigning all armor for a specific race. Right now they mainly just scale the size of the armor, and maybe change design for ears etc, but if they went with some the races that you want, they would have to completely redo all armor for them.

There's a concept art for like an aquatic race here, and I like that one. Another aquatic one I kinda like, is this one:


If they change the feet, they could be pretty cool IMO, and they look very different to what we have, without making it a total hell for the developers to make gear for.

EDIT: picture was bigger than I thought lol