You won't find a SCART lead that's 30 feet long. It's perfectly possible to connect via coax over that distance though.
What you'll need is enough cable to run to the other TV (obviously) and a coax splitter. Cheap ones cost about a pound from B&Q, although more expensive ones will let you do this without losing signal.
Naturally you can only watch one cable channel at a time, but this should do what you want it to