I had Vonage unlimited to Nepal, but cancealed. I have account with Raza.com whenever i need to call i buy from them and can tell you they are the most reliable phone card companies around.
The main reason to canceal my vonage is ........ its lot cheaper to get a call from Nepal than calling to Nepal from USA.
Nepal telecom has Rs. 2.00 per minute rate to USA now which is less than 3 cents per minute and they can call whenever they want direct from thier phone no matter cell phone or Landline.
so, why we are even discussing either you get it for 8 cents per minute or 11 cents per minute.
To OP: your claim of cheapest and most reliable is really? i am not buying you, sorry.
If you really need to buy a card for Nepal. go with Raza.com