[Suicide Junkie]

All the same things apply to the Full-nacelle system.

The only difference really, is that the speed is dependant on your reactor, and not your nacelle configuration.
You just need enough nacelle(s) to enclose your entire ship in the warp field, and then you throw bigger and bigger reactors into the ship to go faster.

The reactor would provide a lot of secondary abilities too, any of which could be used to make AI choices for less-than-maximum speed ships. If you like.