I've pitched beers that are similar directly on a yeast cake with excellent results. Not thinking I'd pitch cider on a brown US05 cake. I'd just go buy new.
As far as harvesting goes, like everything else in brewing, there are as many different techniques as there are people. I choose not to wash my yeast. I just scoop it out of the bottom of the fermenter into sanitized pint jars, making sure (almost always is) a beer cap over the yeast, cover them, and pop them into the fridge. A few days before brew day use it to make a starter and voila!
Good luck and happy cidering!
{edit} Do a search on the forum for yeast washing and cider yeasts. LOTS of good info! 