email and web site certificates

I've decided that we have sufficient content going back and forth in email that should be signed with a certificate, so I've started the process of discovering who to get it from, and best implementation ideas for a smaller organization.

I'd like a certificate for email, our web site, and to use internally for things like the HMCs etc.

Do you have favorite providers? While the low cost provider is not necessarily a concern, I can't afford Verisign either.