Search ebay daily and look for people selling them with PSOne combos. People usually put up old stuff on ebay and some of those things are PSOne bundles with the screen.
Be aware that if you're buying from the U.S., that we have have different video signals than in the UK. If the screen is NTSC (American), then you'll need to buy a U.S. system and games in order to be able to use it. If it's PAL and you already knew that then disregard what I said.