Frozen DE, What's the deal?

Hi ladies:)

I'm fairly certain I want to use frozen DE because of cost and cycle timing.

My questions are (several):

Can you use any frozen donor bank in the states as long as they can ship to your RE and do most RE's work with any frozen donor bank?

Has anyone had experience with this?

What are the most reputable ones, (frozen donor banks)?

Has anyone used a "package deal", set price with refund if no live birth, and how did it go?

Thanks SO MUCH!!!