Alec Baldwin‘s posh Central Park West apartment is slated to go back on the market tomorrow for $9.5 million. The co-op in the twin-towered El Dorado boasts 3,000 square feet and views over the Central Park reservoir, reports The Post’s Jennifer Gould Keil. Baldwin is an Upper West Side loyalist. However, his yoga instructor-girlfriend, Hilaria Thomas, is not. He recently told us she prefers downtown and the commute’s a pain. Sources said Baldwin is “a good way along” in his search for a new pad and is focusing on SoHo. Now that the long time bachelor appears to be settling down with one woman, it seems a new downtown apartment is in the cards, too.