My old boss when I worked at Guitar Center was the bass player for the toasters for a while, and one of the coolest dudes I've worked for. I know that he played a Musicman SR5 with them. Rig wise he mentioned a 400+ through a SVT610 on a european tour, and he now plays a SVT4 PRO through an Eden 210 and 410, but I don't think that was his standard rig with them.
The best player in the toasters bass history was Matt Malles. He's a monster player. Nice guy too.
They've gone through a number of singers beyond Rob "bucket" over the years but Coolie will always be a favorite.
The 400+ was part of a rented european tour rig. When playing in the states, for all the time I saw and shared stage space with them, they had an Ampeg SVT and 8x10 rig, owned by Bucket.