In view of job opportunity and pay scale in Gulf countries; which is good CCNP R&S or CCNA voice ?

Go get them if you have chance. However any ccnp level will be higher than any ccna level, ccnp r&s will promise you a good chance than ccna voice. The pay scale will mainly be based on your experience on such field not only based on the certificate.

CCNP R&S of course because it can give you a chance in ISPs But if I where you I will try to get them both .