They are called (by Liberty) Tivoli lighting. I call them rope lights.
I think you can buy them in lengths, but never really checked into it. The ones in our Liberty were a rigid plastic as opposed to the flexible rope lights you can get at Lowes or Home Depot. I don't think they are LEDs.
I'll bet you can find them in a search on the internet or by calling a converter.
I'm surprised you aren't doing step lighting like Mango is doing with his Martini bar, with lights buried in the surface of the steps so they glow. He did his with fiber optics and other engineering marvels.
