Hi,

Just for info for th rest, just went ahead with Zenith travel since they were the cheapest for the same itinearary compared to the others.
In general, they are very informative during the planning. You can ask tons of questions and they will answer quite promptly.
Payments can be in 4 different forms (CC is only possible if you have an Ecuador CC or you have to pay at the office due to limitation within Ecuador). I paid via wire transfer to their account in Miami and immediately after that I got the confirmation of the payment and later a couple of days later the voucher for the cruise and the Ingala card form for the airport.
All in all, rather satisfied with the service. If you do not like something, make it known, they will try and find an alternative.
I wanted to book a Cotopaxi tour with them after my Galapagos tour, but last minute decided not to due to time limitation here in Quito.

Base on my experience, I would not hesistate to use them again.

Cheers!