Greg H wrote:restaurant?
Say one that wants to give you no more than 36-48 inches of counter space?
It can be done in that amount of space.
Let's also say that a GS3 is out of bounds and the goal is great shots on a budget--primarily because you don't have 20 years to recoup your investment on the 20 drinks a night they sell.
Great shots on a budget are possible in home environments and perhaps even in a very low volume cafe setting, but the prosumer E61 machines one would use require skill and experience from the user in order to deliver optimal results. Furthermore, the steaming capabilities of such machines are inadequate when multiple milk based drinks are ordered. This points to another issue - it's time consuming to make milk drinks for a table of 4 to 6 people - a dedicated on-staff barista is needed.
Chefs want ease of execution, cleanliness, and consistency, (super-auto, pods,); roasters want quality taste and brand protection/recognition.
Two incompatible goals.
Best I can come up with is a decent one group with two mini e's (or one mini e and a major e) and an intense training program for a passionate candidate/candidates.
I'd lean towards a GS3 with two SJ's, a small sink with a pitcher rinser, and a dedicated undercounter fridge. The training program would have to target a reliable and stable person on-staff who will be available to do nothing but make the espresso drinks and the press pot or pour-over coffee. Opting to assign the barista duties on a "whoever is available at that moment in time" basis (e.g. a busboy, waitstaff or bartender) is a recipe for failure.
The only real restaurant (vs. a true coffee establishment that serves light meals as a sideline) I've seen that meets your criteria is Carriage House Cafe in Ithaca NY. They serve breakfast, lunch and dinner, and it is a real full service restaurant, although not in the "fine dining" category (but the food is very good). The important point to note is the fact that they planned a full coffee/espresso bar service into the structure from the onset. Chris Deferio (a regualr on this board and now based in Muncie Indiana) was brought in from his previous position as Barista Trainer at Gimme Coffee. My recollection is that he was involved in the planning and execution during the build-out phase and also implemented/managed their ongoing training program. I don't think it's possible to truly do justice to espresso in a restaurant setting without making that kind of commitment and investment.