We used Simply to Impress and loved it, but the company you might be thinking of is mpix. That's where we're about to order the prints from our photoshoot from. If you sign up and wait a couple days, they'll send you at least a free shipping code. They also have new codes out every couple days.
Re: Making invitations online
I dunno. Dummy here hand made all of P's 1st b-day invites. LOL (Don't do that!!!)
I used Tiny Prints for everything since O has been born-they are great.
Edited: Mommy Brain Fail.