A 580EXII and a 430EXII stay in the camera bag along with a Cybersync transmitter and 2 recievers. The 430 needs to use a hot shoe adapter or can be fired via the 580.
I use 4 Opus studio strobes that were bought as kits of two that include stands, reversible umbrellas, barndoors, grids, snoots, jels and storage bags.
I can use the speedlites with the studio stands and umbrellas if I want to travel light.
,,, and reflectors/difusers