Jon suggested Costco and I briefly looked at the options initially but didn't see any front/back options there. However, when faced with the expense of Shutterfly again, I considered printing out both Christmas and birth announcement cards separately from Costco (can't beat $35 for 50 cards) and luckily stumbled upon a few front/back choices. So for the low price of $35, this is what we went with (minus the text boxes - I can't find just a preview option without them):
The best part about these? I was able to have our return address printed on the envelopes.. fo' free!! You don't even know how excited that made me. I will definitely try to use Costco in the future!