If as a sole buyer of a new corporation via the SBA 7A Loan program, your number one goal is to pay off the loan as quickly as possible and therefore accept a small salary and no annual distributions, then isn't a C-Corp the best legal entity? A pass-through entity's ultimate tax rate is 40% WHILE a C-Corp's tax rate should be 21% thanks to the Tax Cuts and Jobs Act of 2017.

As an example, if your yearly loan amount is $200K of which $100k is principal and $100K is interest. In a pass-through entity, the tax liability of the loan would be around $40K. While is a c-corp the tax liability would be $21K or almost half. Am I missing something?

Also, after the loan is paid off would it be possible to change the C-Corp to an S-Corp?