Probably want south of the cut, and most likely a "villa" type accomodations. Paradise Tradewinds, Paradise Villas, The Palms, Coral Bay Villas, Banyan Bay, Caribbean Villas all come to mind. Some have pools some don't. Those without pools have decent swimming and sunbathing areas in most cases. The thatched roof affairs, although great for a picture and to talk about back home, aren't quite as "Caribbean Romantic" as they might appear. Villas are generally much larger, brighter, and have the full range of creature comforts. Just my humble opinion.
Nothing's too far in SP, unless you get WAY north of the cut. The lodgings mentioned are all within very easy walking distance of nightlife (if one is so inclined).