Sending email to certain kinds of members only...

Currently my group has 4 "self-classified" kinds of industry professionals according to the question they answer when first joining our groupsite. Basically it works out something like this:
a) Sellers
b) Buyers
c) Both (they buy & sell)
d) They are professionally involved with serving buyers, sellers or both.

So my question is:
If I want to send an email blast to all the Sellers (see group "a" above), how do I do that? 

I know how to send a general email blast to all member in my group, but if I want to send an e-mail (or newsletter) that is geared for only one or two kinds of pros in my group, how would I do that?

I suppose I could export the database, open it up in a spreadsheet and try to "hand pick" all the Sellers or Buyers, etc. but that would be a very laborious and time consuming project, not to mention susceptible to "tired eyes" and human error.

If this feature doesn't exist now, will it be available with the new version rolling out next week in September?

Thanks!
Michael