If your 125 is the standard dimensions, keep in mind that all pbass, even the smallest onces will grow to a length greater than 18" during it's life span.
You would need at least a 24" depth tank even for the smallest pbass for life. Control feedings when they get bigger if you don't have the $$ for a bigger tank.
Most people who start in Pbass don't stay with pbass. They generally sell them off before they ever hit the 12"+ in my opinion.