So I'm starting get prepared to order the invitations as soon as I get the final okay from the church that the time for the ceremony is not going to change.
I just noticed yesterday that they offer an Envelope Addressing service as well. I was originally planning on using InkSpun.com but turns out that InvitationsbyDawn is much cheaper option (at least for me since I'm ordering from IBD.com) - they will address the front of the envelope and the back flap for $38 per $100 invites (I have 92 so that's perfect).
I just emailed their customer service to ask them how I go about ordering and I would have to call up to place my invitation order and then email the template on their website with the addresses. I also asked that since I was going to be ordering over the phone would they still honor an online discount code and they said they gladly would and just mention it when ordering. Very quick with the response time as well!
Just a little tip - it so awesome to think that once the invitations arrive I basically just have to stuff and stamp them and I'm done!
Here is the link to ther addressing service: http://advice.invitationsbydawn.com/2009/03/let-us-address-your-envelopes.html