I'd suggest the programable Sansamp - gives you the ability to set different levels (or sounds) for two basses...or have a mute setting etc It can have a dramatic effect on your sound, but it doesn't have to if you set it to taste.
Also, when you find engineers that won't use your amp's DI (because "its noisy".."sounds crap" etc etc) they will often agree to use a Sansamp..mainly because they recognize it.
I wouldn't carry mics and stands.
Worth adding another cab..or getting a used 4x10 for those backline only gigs. If you are traveling a lot, consider leaving your current cab at home and having one living in the van.
Enjoy! but don't forget the earplugs...