I am buying air tickets for my parents, who are in Kathmandu, to come visit me here in the US.  I am sure there are many here in Sajha who have done the same.  I have some questions to them:

Nowadays, travel agents give out only eTickets.  If I purchase the tickets here and send the itenarary/details via email to my folks, will they be able to travel just with that?  Will that printout be sufficient for them to get boarding passes and, equally importantly, will that be enough at the Port of Entry when they land in the US? 

Alternatively, is it possible to get actual paper tickets at the airline office in Kathmandu if they take the itinerary printout there? 

Are there any potential complications that you see?

Thanks.