[asterisk-users] USA Origination recommended service?

[R.R. Libera]

Hello,

I need an advice about USA Origination (only). Who you recommend to me 
for a production environment like a customer care support?

I need:

1) Excellent call quality.
2) Stability.
3) Excellent support.

What will be the best increment schema? 60/15, 60/6, 6/6 ??

Thanks in advance.

R. R. Libera.