As you stated in your original question, to file a Form 1041 tax return for the estate you would need TurboTax Business. But that has nothing to do with your personal Form 1040 tax return. You cannot use TurboTax Business to file your personal tax return. You would need two separate TurboTax products - TurboTax Business for the estate, and Premier (or whatever version you want) for your personal tax return. Using TurboTax Business for the estate does not complicate your personal tax return.
You cannot upgrade from Premier to TurboTax Business. They are two separate products.
Also note that Premium is a TurboTax Online edition. The Desktop TurboTax Editions are Basic, Deluxe, Premier (not Premium), and Home & Business.
