Alex, I really like what you did with the lighting in the bottom image (wonderpus) on the link you provided. So it sounds like you took a 60, 105, and 150 macro to Lembeh and shot all 3 on a full frame sensor camera? It's a given that my 100 will get the most use, but did you find the 50 or 150 to be more useful when you were there? From your comment referring to Lembeh as a destination for the "bigger small stuff," I'm guessing the 60? My main concern is if my 100 on full frame will suffice for pygmy seahorses, or would the 150 be better here?
I do have a Sola focusing light in my kit already.
I was last in the Galapagos in 2005, and from what I hear, things have changed a lot since then. I did a 10 day trip on the Sky Dancer (a Peter Hughes boat when they were an independent company). I believe this boat is still around and is now called the M/V Galapagos Sky and is operated by Divencounters. This was an excellent boat and operation back when it was part of the Peter Hughes Dancer fleet. Back then, more shore excursions were permitted by the Ecuadorian government, and we made daily trips ashore on multiple islands, while still managing 4 dives a day. Liveaboards in the Galapagos have always been pricey. If you can afford it, just go. As the previous poster said, it's fantastic. The visibility is generally not spectacular (don't expect 100ft of viz), but it's still pretty good. The better sites averaged 40-50ft of viz when I was there in July. Also expect a range of water temperatures and moderate to extremely strong current at most sites. The payoff is some of the most spectacular shark and big animal encounters you'll ever have underwater. It's definitely worth it.