Alternatively, if you want to experiment and explore options a bit you can buy a bottle of Weston's Old Rosie cider, let it sit for a couple of days to allow the yeast to settle at the bottom (its a bottle conditioned cider) then drink the cider but leave about 1/4 - 1/2 inch of liquid in the bottle. This can be nurtured and developed into an excellent yeast using apple juice and a little sugar.
There is an excellent thread on here which lays out the whole process i think by calumscott. I've been using my recovered WOR yeast now for a few generations and its still working very well. I've even re-generated yeast from a bottle of my own cider.