This may be a trick question, but I suspect the answer is Sydenham. I don't think Negretti & Zambra became photographers to the Crystal Palace company until 1854. They were not mentioned in Phillips' 1854 guide, but are in the 1856 edition.
Incidentally, Samuel Phillips had strong Sydenham links. He spent the last couple of years of his life (1852-1854) at 48 Kirkdale, and is buried in St Bart's churchyard.