Used Acoustic B20 vs. New Peavey 158 MAX Bass Amp?

Both are 99.99, the acoustic (brand name) is a used 20-watt sold at guitar center. 1000 ft. away the nearby indie music store competitor Willis Music has a new (not boxed up new but warranty included) Peavey 158 MAX. I have a Behringer 15-watt guitar amp that is pretty old, still loud but has lost most of its distortion. My roommate wants to pick up the bass and play along, I am shooting for a metalcore project. I can't make up my mind about which bass amp would be better. I need something that will be loud enough to compete with the guitar amp and cut through that has decent tone. I will be playing with a stagg sg bass. When it comes to laying down nice metalcore-ish bass what would serve me better between the two? PLEASE DON'T TELL ME TO WAIT, OR BUY ANOTHER PRODUCT. JUST ACOUSTIC B20 VS. PEAVEY 158 MAX. Thanks. By the way, again, I am not trying to tear down the house, we are just playing in a small room jamming together. I have a Behringer 15-watt that is over seven years old. I just a need the better of the two to go along with it. And lastly, yes, we may mic the amps for recoriding an indie metalcore project.