I think you may need to rework things here.
Your brief is a full on 2 group brief (at a bare minimum), not a compact brief. You will not get the performance you desire from a compact machine at 10A as recovery will be too slow and you will run it down. 10A just cannot heat that quantity of water in that timeframe.
As for volume, realistically, a good barista might turn out 60 an hour- so if this is really what you think you will do, youre talking 3 staff with split duties and most likely a 3 group machine or 2 x 2 group with suitable provision of power.
Sorry to bring bad tidings, but this workload calls for 15A at a minimum. If it was my gig, Id be specifying high capacity elements as well. I think its back to the drawing board...