Let the PCR buffer concentration be anything you need to dilute the PCR mix 1X (final/working conc.). You need not worry about the buffer conc.

For all companies products they supply sufficient literature follow that.

Good Luck!!

(https://www.gbiosciences.com/image/pdfs/protocol/786-449_protocol.pdf)

Still any doubts check my RG question answers patiently (answered many) or you can ask me.

The answer on the Biosciences site :

UNIT DEFINITION

One unit (U) of Taq polymerase is defined as the amount of enzyme needed to catalyze the incorporation of 10 nanomoles of deoxyribonucleotides into acid-insoluble material in 30 minutes at 74°C.

COMPOSITION OF THE TAQ MIX

Taq DNA polymerase is supplied in 2X Taq buffer, 0.4mM dNTPs, 3.2mM MgCl2 and 0.02% bromophenol blue. Taq mix buffer is a proprietary formulation optimized for robust performance in PCR.