@Sirus_me: Only required documents for H1B stampings are : Passport, I-797, I-129, LCA. Any other documents you bring will be supportive documents. Besides above documents I had vendor letter stating I am employee of the XXX company and working on the XXX client. I didn't have client letter. I had tax filing for one year but at that time I was working on  OPT. And I put all acadamic certificate, all paystub I had(i would recommend you to bring at least 4-6 of them), All I 20s and what other documents you have and you think will help you to make your case strong. Last but not least, when being interviewed, try to convice VO that you are related to your company not to the vendor or cleint.

Hope this will help you. But still I recommend you not to visit Nepal or anyother countries unless you have to. Waiting time for visa is so stressful eventhough you get visa after few weeks. Also, get prepared for the time it make take. I heard, for some people, it make take upto months.

Jhilke