HR 25 works hand in hand with repeal of the 16th Amendment. The two are completely intertwined.
Intertwined but not inseparable. Repeal of the 16th (or any amendment) can not be done by an Act of Congress. It must follow the constitutionally described procedure for amending the Constitution.
I would not put it past congress to institute some form of national sales tax but also leave the 16th Amendment in place.