The english defenders whose names you've mentioned have never been purchased (or even just courted) by major continental european sides. Boumsong has.
In case you forgot, Woodgate was bought by Real Madrid.
Not many English players go abroad because foreign leagues really aren't attractive to players. Spain is the closest in style and in recent seasons players have gone or been linked there. The French, Dutch and German leagues aren't close to the standard of the Premiership. As for the Italian league, it lacks thepace and excitement of the Premiership, not to mention the widespread corruption.
Another major reason English players don't move abroad is the inflated prices. Until English clubs get realistic, the decent players will only ever end up at LFC, Chelsea or Man Utd.