Need advice on the best options for Payment Gateway and SMS Gateway Services for website.

Dear Group,I need some info on the best options for Payment Gateway and SMS Gateway Services for a public web portal.
I have got few names on the Internet like Valuefirst, clicksms, etc but need to understand the pros & cons of each and the evaluation criteria (if any analysis is available) from those in this business or those who have researched and implemented these solutions and have good experience to share on them.