I am currently using an iAMP 500 with a radial bigshot ab box (which has a tuner/mute and level adjustment on it...great little ab box) a Fishman Pro Platinum EQ into a Berg HT112 and sometimes I put an EX112 under it for more ooomph. I run my kay w/ a realist into the Pro Platinum into the ab box and my Zon into the ab box and then switching between the two is very easy and quick...and I just stomp on the tuner/mute to tune quietly. I also will use an Epifani UL 502 with a Pollman upright w/ realist into a pro platinum eq into one channel and a Zon into the other channel into a Berg HT112 as well and that is a great rig to do doubling gigs with. There are so many variables involved and so many good products out there to choose from. If you can actually get to a store with good bass gear, sit down with your axe(s) and ab everything and choose what sounds the best to you. Sometimes certain gear can sound great on paper, but can turn out to sound not so hot when you actually sit down and play through it. Hope you find a good setup that works for you.