Dropdown list with hundreds of options



I'm trying to find a way to have a Drop Down or pick list that is extensive in nature. The list is Customer NAMES, where users can select from in order that the Spelling is always consistent. Currently, the cell is Text cell and user manually enters so if it's slightly even a character off by say a "." or ",", it impact the way dashboard count or rollup the customer data. Using a dropdown list doesn't appear to be good solution because of the sheer number of potential customer names (in the hundreds). So I want to create a data source sheet that holds all the customer names. This source sheet can be updated by Admin when a new customer is added for selection. When a user selects a customer, it will pull from list. Does anyone have suggestions on a way to do that? I read about Data Table but we don't have Control Center currently and that appears to be only available with Control Center. Much appreciate the suggestion. Thank you