You should search for threads before starting a new one.
http://www.dakkadakka.com/dakkaforum/posts/list/620462.page
in short no, you can't have O'Vesa, Farsight, Buffmander attached to a Riptide. Then comes the
RAW/
RAI debate of O'vesa, Farsight, Buffmander in any other unit which is covered in the link.