Well, for a basic install for MP to work, install these things in this order for it to work. Kobarashi Maru 1.0 is MP compatible:
1. BC
2. BC 1.1 Patch
3. Kobayashi Maru 1.0 (it includes the Foundation which makes modded ships work in BC)
4. Any other BC mods (except for Supermod 3, it is Single Player compatible only and really doesn't like other mods being installed on top of it and it would also overwrite the majority of the KM ships).
BCUT has replaced BCMP and BCMI completely and is much more efficient and has no known bugs (and if there are they are easily fixed by its creator).
Kobayashi Maru 1.0 is a very big download and last time I checked is not on BC Files due to a rule introduced involving copyrighted music. There is a link for it elsewhere but I do not have it.
KM itself is a very good mod pack, giving you a large range of ships for all races and adding a lot of other races as well. It contains all the big mods like NanoFXv2, DS9FX 3.0 and lots of other little trinkets which are fun to use ingame.
And like I mentioned before, it is all MP compatible but is recommended that you create to seperate BC installs, one for adding lots of mods and the other for MP'ing (so the only mod being KM 1.0).
I think that just about covers it.