Thanks for the reply!
I cannot find any 30pF for breadboarding..
I found 27pF:
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=338257&Row=256525&Site=US
and they carry 33pF:
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=338569&Row=256670&Site=US
Order both, and see which gets you closer. Remember, the 6pF number was just a guess.
What would be a better option? (So I assume all the crystals in my previous email would work with the same caps..)
I didn't check through them, but if they all say 18pF, then yes.