AO Nang is great, but the beach there s*cks. It's 2 ft deep a 1/2 mile out. Can recommend Ao Nang Villa. Great beach at Railay, but a boat ride. That would be a good place to stay, but I don't know if there are any high end accommodations now (haven't been in 5 yrs). It had more of a 'hippy vibe' when I stayed there. That leaves the Meridien Khao Lak & Sheraton Krabi (since you're SPG). I like 'em both, with a small edge to LMKL. Plenty of stuff on both of them here on FT. wj