Ha! Invading another of your threads. Serves you right for helping me out with African bird id back in April.. Cheers for that B.T.W.
If you can, I would suggest doing what I do and visit a local firm if you can. Sit down with them for a few minutes and go over the design and get an idea of it right up there on the screen as you talk. If you have your own design it will save time and money. One thing the girl did say was too many people design a card that is too busy. She was glad that I'd kept it clean and simple.
This is what I did after checking out others that were listed on the net and didn't find anything I liked.
Okay, that's a lie, I didn't do it. I was at work, but my girlfriend did it for me after I jotted a basic outline down. Good isn't she?