I have a healthy and huge Magnifica anemone for the last 2 years. In my experience it is good to get a healthy one, but not critical, in fact, in my experience these nems are pretty hardy.
I got the anemone at a show, it had a sticky foot, but not that sticky tentacles, brought it home, it refused to stick to anything, blew up like a balloon, got caught in powerheads TWICE and shredded up pretty well. I stuck it in a basket near the surface and pretty much force fed it rods reef and fish bits. It healed, it got stickier, I put it back in the tank after a month, it stuck its foot down, and it has not moved in over a year.
It has grown significantly, is fed a silverside once a week, and is a great home to our two snowflake clowns.
good luck!
EDIT: wow. really reefcentral? I cant even post a pic that is hosted over at another reefforum? You arent the only forum, it's ok. good grief.
I'll try again: