Obviously you can use any kind of coffee. At first you would tend to use expensive and aromatic coffee but after a while, you'll find it too costly to continue buying and you'll end up buying the same old ordinary coffee.

So practically, it all boils down to your own affordability.

In my previous experience as hotelier/F&B provider..i would recommend you to use SAECA by BONCAFE coffee espresso machine
http://www.bonc…
as it is among the best, easy usage & maintenance,
plus it make great fresh brewed coffee & espresso!..you can make cappucino at the same time too!..

Those sold in supermarkets are meant to be used at home where usage volume is not high thus it will not last longer in cafe business like yours where demands from these kind of beverages are high.

The best thing about this brand, it also comes with it own coffee brand Boncafe http://www.bonc… which i simply love the fresh taste and smell..there many kinds of coffee they produce such as Arabica (my favourite).

Hope this will help!