There can be several factors to consider for purchase of a espresso machine, whether for home or for business. The bottom line is to consider the following:
1- Whether the business will be coffee based or it will serve coffee as a part of food service. If it is a Coffee shop, you should start with a 2-group machine.
2- Location- Busy foot traffic in excess of 50,000 people walking by or less can keep the store busy. Think of a 2- group.
3- Funds available for equipment. I do not recommend 3-group machine for any business. That is a waste of money for capacity that will not be used. If volume is high, go for a superautomatic.
The excitement of starting a business can lead to purchase of expensive investment with capacity much higher than what you may need. There is absolutely no need to purchase new expensive two group machine. Start with a one group commercial machine with boiler size of 6 to 8 liters. Check out brands like Rancilio, Fiorenzato, Nuova Simonelli (Price range $1600 to 2000). The machines are reasonably priced, parts are easy to find and service techs are available easily. As the business grows, buy another one group so you will have flexibility with two groups, independent machines placed next to each other. If one goes down, you still have one to work with while the other is repaired.
Espresso machines are over-priced. Be careful where you purchase and and do not pay attention to big brand names where you pay high price for the name and get no advantage.
Home espresso machines have a limited use and will not keep up with the requirment to be 'on' for extended hours. The size of boiler is small and will not supply enough steam.
Commercial superautomatic machine is another choice if and when you can afford. The superautomatic espresso machine of Fiorenzato is an excellent choice in the range of $9000.00.
If you are handy and can fix minor problems in the machine, you can also find a used 2 group machine. Find any simple machine for which parts and service is available without need for exclusive distributors or technicans for service. That will be a expensive slavery that no one will talk about, until you disover after the purchase. Keep away from the "exclusive".
Good luck.