Try these http://r.ebay.com/DjQPwj
or try these http://r.ebay.com/jW0h5f
be carefull with these! These chips are 3,3 Volt.... you normaly should use 5 Volt Modules! 3,3 Volt is not available in the Amiga!
to run these chips outside there spezification is on you own risk....
They could work, but no idea how long they will.