While it is not as fancy ( and probably not as well designed, nor as heavy) as skyrunner's ship, my interplanetary ship Kerbin one continues to be built.
I just added a dedicated fuel module which increases capacity to 9000 liquid fuel. it also adds more RCS thrusters, which will be very much needed to spin this thing, and more RCS fuel ( but that will be true of all other modules, since RCS is needed to dock). like RCS, fuel, each new module will most likely add a bit more fuel storage as well.
as time goes on, I find several mistakes in my design, which will be fixed whenever I'll want to build another ship of this size. for example, complete lack of lights. and I should probably have added some more supports.
now I am missing an RCS storage/power module and a crew/communications module module. power module will also likely have docking ports, to allow refueling missions. which is a must if I manage to get it to fly, because I am not going to build more interplanetary ships than strictly needed.
by the way, skyrunner, what kind of engines power your ship?
also, I can't see many docking ports. how big were the modules you sent into orbit? any chance you could show us your launchers?
edit: 2 small notes.
1) I am still surprised by how easy those modules are to dock. much easier than my past ships, in fact. must be better use of docking commands, coupled with lower acceleration thanks to mostly pure RCS thrust and higher mass.
2) I am half worried that the end result will have too many parts and start lagging. still tuns smoothly, but I have much more to add.