Depends on how much you're prepared to pay. But I found quite a lot through a Google advanced search, typing in
flashcards and
EFL as the main words,
add to basket as the obligatory phrase and
Longman, OUP, CUP, Macmillan, Heineman (and any other publisher which comes to mind) as the "
one of these" choices. They mostly seemed to be for children though.
There are also some good ones published by Ladybird, not for EFL, but designed for kids learning to read. Lovely pics though. I got mine in the UK, but their website is
http://www.ladybird.co.uk/ However, I also saw some of their stuff on
Yahoo! auctions. Try there and on
E-bay. You might pick up something more cheaply.
Hope you find something.