can try enom.com
or try the name finder tool i made years back
http://www.domainpendor.com
(free download) basically you can make a word list
and then have it append things
for example i have a power word list something like
top
best
fast
etc.
then i put in my suffix as say host .com
and it generates
tophost.com
besthost.com
fasthot.com
etc etc
can do prefixes as well...
then take the list to a bulk generator site such as dotster.com
and check to see whats available