[Suicide Junkie]

Just have one SY for each component. Then they all finish relatively quickly.

If you really want speed, try a retrofit series:

Build an empty Space Station hull in a few turns, then retrofit it to a 40% more expensive design, then 40% more, and so on.
Keep designing and retrofitting during the same turn, and you can build it up to an empty hull with the Sphere's component on it.
Next turn it is repaired, and you have your sphereworld.

WARNING! Retro series are incredibly expensive to do. You can easily spend much more retrofitting than building from scratch. Do not attempt this on a tight budget.