What would be your preferred choice? The pdf files will contain mainly text.
For relatively simple, straightforward, "mostly text" PDFs I'de use fcl-pdf: it's relatively simple, doesn't have external dependencies, has most (if not all) of the needed features, and is already included in Lazarus/FPC.
That said, note that I've never used any of them for serious work; I tend to rely on a system-wide PDF "printer" instead.