Yup, they are H.kuda. Unfortunately, they are not true captive bred specimens. Sadly the only H. kuda on the market are being supplied by net pen farmers in Sri Lanka and Vietnam. They horses are raised in net pens in the open ocean, so esentila from a health stand point you just bought wild caught seahorses.
I hope you QT'd the new ones before you added them with your existing H. reidi.
As for raising the fry, I can tell you that those to species are the most difficult fry to raise. They are basically the same when it comes to their requirements. Neither one will hitch for at least the first 2 weeks, they require very small first foods in the form of rotifers or the small strain of baby brine shrimp.
Here is a fairly good article on raising reidi fry if you are interested.
http://forum.seahorse.org/index.php?showtopic=8203