Bookcellars rhymes with:
bestsellers, cellars, resellers, sellars, seller's, sellers, sellers', bestsellers, cellars, dwellers, ehlers, ellers, fellers, heller's, keller's, propellers, resellers, sellars, seller's, sellers, sellers', spellers, teller's, tellers, zellars, zellers
Bookcellars sounds like:
bachelor's, bachelors, booksellers