I have read on here about phones that can use other carriers. Sprint is horrible where I am. Thanks!
Go to Coverage Check | Republic Wireless , type in your zip code, and see what is recommended.
To add to the above answer, yes, Republic also offers coverage with T-Mobile on all phones that are offered. If you would like to know 100% you’ll get T-Mobile you can choose from the following phones that ONLY operate with them: Huawei Ascend 5W, Galaxy J3, Samsung Galaxy S6, Moto Z or Moto Z Play
Or, go bring your own phone since that’s currently GSM only no matter the phone: Bring Your Own Phone FAQs. I do realize the OP asked about buying from Republic but still worth consideration.