My Info on the Galapagos will be a little dated, from 2003 but at that time you could provision fairly well there. Yacht agents would come out to your boat in the anchorage and arrange to bunker, and water you. There were several good shops for fresh food in town. They use the american dollar as their currency, and most items were well bellow american prices. (Beer was surprisingly cheap.)
Jimmy Cornell's web site: www.noonsite.com
may have more upto date information.
The pilot charts are the best source for exact information on where and when to find the trades. (http://www.nga.mil/portal/site/maritime/
) We found they are roughly 24/7 at 15 to 25 (like I said before - a lovely sail.) If anything they tend to freshen a bit at night.
Took a look at your blog, and you have done quite the project on Trim. Excellent work on the deck. Although if you hadn't said you were an engineer I would have guessed it from the costed BOM's on your blog. (You supervise 50 engineers? Man you are living my nightmare - been there, done that - burned the t-shirt.)
You won't regret casting off when you do. Fair winds.