I like both Marjorie and Margery, though I'd go with Marjorie for family reasons. I've been told that Marjorie is more likely to be Scottish and Margery English, but I can't prove it and I don't much care.
I think it's highly usable, with a pretty appearance, sound and rhythm. The only thing that puts me off is the ghastly possibility of Marge, or Margie. Forget the Simpsons - they were awful anyway.
Spellings. I've never seen Margorie, and I hope my luck holds. I did know a Marjory once, who did her best to persuade one and all that it was the original, traditional and best English spelling. She was a lovely woman, but the spelling still looks wrong to me.