As people have already stated this can easily be done with parts already in the pack, thusly: And yes, I always tend to build the entire thing in the VAB then send it up in chunks... just to make sure it all fits together
The size of the KSOS mods are really not the issue. I run them with KW, Nova, Karbonite and a bunch of others without running out of RAM, and i'm still using 32bit...