Marcie, if I went to your church, I'd suggest substituting communion wine for straight espresso shots. Especially for the early service. You'll need super-automatic machines.
We wholesale to a Church in Naperville, they have just finished expanding their cafe and adding more seating. Their cafe is set up mare to serve and foster community than to make a profit. Drip coffee is free, they have volunteer baristas and sell espresso based drinks. The goal was to have lattes and mochas ect. offset the cost of coffee service. They have never quite made that happen. I'm sure they would be happy to talk to you about their experiences shoot me an email and I'll get you their contact info.
my good friend Josh Weidmann consults specifically for this subject and he is a great guy as well. Please contact him, you'll love his input. Check him out on google too, he's got an amazing ministry.
i've heard of this being done quite a few times (in plenty of local churches from every denomination) most of these churches use their in-church cafe as a platform for youth groups, ministry meetings and after mass but solely for the congregation.
however, there are also a few cafe (here in michigan) that have implemented a cafe that's also open to the public. the best example i can think of is The Common Cup cafe (http://commoncupcoffee.com).
hopefully that helped.