Here are a few suggestions:
Archie Stark (soccer) - record holder for most goals in a season (61) until Messi broke it in 2012.
George Best (soccer) - legend, legend, legend - if Upper Deck doe not own rights.
Gordon Banks (soccer) - arguably best post-war GK ever.
Ricardo Zamora (soccer) - great pre-war legend. would have been in the original 1930's series if it was international.
Dixie Dean (soccer) - Everton, pre-war legend (see above)
Alex Jackson (soccer) - played in USA and became legend in Britain
Kenny Dalglish (soccer) - King Kenny !
I would buy this series for a chance for any of these cards.