Rishi Sunak is by far the better candidate in that he has been Chancellor of the Exchequer throughout the recent pandemic. He is committed to sound finance and, being very wealthy, is unlikely to be corruptible.
Liz Truss, the current Foreign Secretary was a former vociferous backer of the remain campaign but now says she was mistaken and supports Brexit. She also supported Boris Johnson till the end of his premiership.
Whilst Sunak says he will not cut taxes Truss has promised to reverse the recent increase in National Insurance and cancel the proposed increase in Corporation Tax. She has also promised to increase defence spending to 3% of GDP. She intends to borrow the money to cover these costs and then recover the money by 'boosting business' without specifying how.