which video synthesis modules are you intending to use?
which case size?
how many psu3?
the psu3 was one of the recommended power supplies for lzx video modules... but note that video modules are usually power hungry... new lzx factory built modules can be run directly from a 12v wall wart - or via a splitter module (or cable) or from a eurorack power supply... so it really depends what you intend to run and what else. is in the case...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities