I was trying to make a ship to launch all the science instruments I have into space (lab, 2 barometer, 2 thermometer, 2 goo, and materials bay). I don't have any mods yet except for mechjeb
The 3 boosters seem to be unnecessary \ don't help... but it makes going into orbit (i skip kerbin's orbit) a lot easier.
My orbit below might be a little weird, almost hit the moon on my way up.
Below is the orbit
Above is the ship in orbit, and below is the setup I used. the outside runs out of fuel, then the center rocket, then the middle circle
Still searching for that magic 15k+ deltaV rocket. I play very casually though, so haven't done much math \ tinkering. You can make this setup with more FPS if you do with out the boosters, and maybe add another ring of fuel and mainsails? Haven't checked yet
The ship file is below... forgot to put struts on the top, won;t work with mechjeb when it moves around so much. Then again mechjeb managed to rip one of the rockets off my ship in the 20 seconds i left the room lol