I think walletbuilder can do this job for you,they are a very popular coin and wallet developer and some of the top crypto currency which has proof of stakes are their clients,but feel free to ask others and compare and choose the best one that can give you the best package and satisfaction.
Thanks for the reply. I think i contacted them already and currently they said they do not work with POS3 or POSp.
Igotspots - i'm not sure he is a coder himself but got mullick to build his coins. Although thanks for the suggestion and I could be wrong.