Joe Hill wrote:

Are there seconstructed proto-Centum and proto-Satem languages?  If so, is there anywhere I can find information on them?
Aside from (satem) Proto Indo-Iranian, I doubt it.  The other centum/satem languages reflect independent development, I think (IE is not my field). 
Two very useful IE websites:  -- this is, I think, "The Indo European Database" -- and a mailing list -- I hope that works; otherwise find the "yahoogroups" site and enter "cybalist"in the search box. I think you have to join (no big deal) in order to read the messages. (11,000-plus archived)  You could post your question to Cybalist and get an authoritative answer.