David, I had an agency organize the Costa Rica itinerary for me. They booked the hotels, transfers (by vehicles), and a few tours.
I usually arrange all these things myself and had been to Costa Rica before, so back in November I started to look at eco lodges to book my own trip. But that soon became way too complicated. It takes a LOT of effort to research each place. Their websites mostly just say how much you will enjoy it instead of providing needed info. So it meant looking at reviews, checking proximity to parks, etc. It got too time-consuming. So I went with Costa Rican Vacations which I had used before. It went great - only one snafu (the hotel had me for 2 nights when it should have been 3) which I was told was the hotel's fault.
If you go, consider visiting three or four different regions, because they will have different birds and other critters.
CR is a small country, but travel times can be long, so allow time for that.