2 and 3 look to be reidi but it's hard to tell from those pics, could be kuda. Both are definitely males though. I can't tell anything on the first one. Is it possible to get a side profile of the heads? The coronet is the easiest way to differeniate between kuda and reidi. Kuda have a higher more rearward sloping coronet whereas reidi is lower and not sloped.
Take a look here for some pics of the different species.
http://www.seahorse.org/gallery/main.php?g2_view=core.ShowItem&g2_itemId=12&g2_GAL LERYSID=630b7e7bb7ace6f1af533ec2790b80b4