If you are setting up a coffee house business that will be open to the public there are quite a number of items that you might want to invest in. You will want to buy a commercial grade coffee grinder. Your customers will be expecting really good coffee and you can give it to them if you invest in a commercial grade coffee grinder.
If you are going to serve them espresso then espresso cups and saucers should be on your shopping list too. You can not serve espresso in regular mugs. You need to have little tiny espresso cups and saucers made especially for this beverage.
You will also want to invest in a large supply of regular mugs for serving hot beverages. From coffee to tea to hot chocolate your patrons will want to order hot beverages and they will need mugs to drink from. If you have a really good dishwasher you may not need to buy quite so many. You can simply have a staff member continuously cleaning the ones that you have. They will need time to dry though so make sure you buy enough.
Maybe for a unique experience, you can brew some stovetop coffee.
You might also want to buy tea pots so that your customers can order a full pot of tea. You can buy either metal or porcelain tea pots. Either will work fine. The metal ones last much longer though and you do not have to worry about them breaking like you do if you buy porcelain ones.
By focussing on some of the basics that you will need to purchase you stand a better chance of having a successful coffee house operation. You will have the right essentials in place in order to carry on a successful business for your customers. Buy great beans and you will be well on your way.