Is it the DS-156,156K,157,and what else ?

DS-230 part 1

And some optional consulate specific forms like (OF-169, or DS-2001) Checklist of items needed for interview.

This is a consulate forum question. Where you posted this has more to do with the period after the prospective immigrant has visa and has entered the USA and before getting green-card.

When you do find out more, you may want to help every one out and update this page: http://www.visajourney.com/consulates/inde...&cty=Panama

I wish I could get time off of work to accompany him on the interview.Since they sent hin all the papers in English,he doesn't understand them,so I am trying to help him fill them over the phone.

I helped my wife by filling them out while chatting online, saved the changes to the PDF files using Adobe Acrobat, and emailed the compleated forms to her, she then printed them out.