I say use the BA miles for a Galapagos trip. It'll be 80k biz/40k coach roundtrip and no fuel surcharge if you book it all on LAN. Plus, LAN has flights directly to the Galapagos. BA is also pretty flexible with stopovers as long as you pick cities near the flight path or points where you're going to have to connect anyway. I've book on LAN with BA miles before and it was pretty easy finding good availability to the places I wanted to go to.