"Are these the only two options for certification?"

They are probably the more commonly known options in the states, beyond the proprietary programs of the two chains.

As for which, it's your choice. USISTD would be more traditional for international style, DVIDA perhaps for american style. No reason you can't ultimately do both.

"also how do I find some one to do the testing, do I bring them in or go there? "

Contact the organizations, they have someone who is in charge of the exam programs.