Highly rated double bass cab maker Mike Arnopol (ask BCer's TheRev and bassace about his cabs) uses a Puma for double bass and electric, albeit with one of his own 4x6 cabs. Acoustic Image heads are great for double bass but completely clean and so you would need a preamp (eg Sansamp BDDI) in front if you wanted a warmer, more overdriven tone with an electric bass (eg, for blues, rock, old school funk). Stick with what you have!