I haven't been to Cocos Island; I have had a liveaboard in the Galapagos (
Humboldt Explorer) and Belize (
Sun Dancer II, subsequently renamed the
Belize Aggressor IV). Neither is what I'd call a macro-focused designation (though the Engineer, Simon, showed me my 1st pipefish in Belize - tiny thing!); my Belize diving wasn't complicated by current and the option for a buddy pair to go off on their own from the group was there. I hyper-linked you to my trip reports.
The Galapagos is famous for big animal diving, often there's some current, and the stereotype is to tuck part of yourself into a cleft in a rocky area so you can hold still despite some current and watch the 'show' (e.g.: teeming life around you, schooling hammerheads, etc...).
The
Cuan Law didn't have get a lot of reports or discussion on ScubaBoard, and I've been hoping to see some since they started a Virgin Islands itinerary. From past discussions, it had a reputation for a broader activity focus and appeal beyond just lots of diving (and consequently was thought to offer less diving than some regional liveaboards). It also looked a bit expensive to me.
@Eric802 wrote that his father-in-law raves about it.
Liveaboard for Non-diving Spouse. Also see Post #8 by DiverSteve.
I wrote all that as though you'll have your pick of the options. You already know that's not likely. The
Cuan Law is one boat; 2 liveaboards service the outer atolls of Belize. The Galapagos has a bunch of boats, but it is expensive, if you're doing airfare arrangements late I've gotta wonder how much that might rack up the cost (though maybe working for an airline you can travel cheap), and I imagine Spring Break is a time when a whole lot of people get a week off from work and travel.
Oh, and with the Galapagos, you may need to fly into Ecuador and overnight in a hotel, then fly on to the island your liveaboard operates out of the next day (and you might spend a night in a hotel there, too). Take a look at your travel arrangements, but if you only get 7 days off, that might weigh against a Galapagos liveaboard.
As much as I love liveaboards, working under the constraints you face, it doesn't sound like the optimal 'solution' for you at this time. What motivates you to want a liveaboard? There are land based dive destinations were one can rack up a high dive count.