Ended up going with a single dipole for CW.

Purpose: Domestic contesting, and H&P during DX contests.

Why coax fed?: Simplicity. That and lack of ladder line.

Vertical vs. Dipole: Has to be on the roof, that's our only approved play area (Fortunately it's on a 50' tower atop a ~80' building), and I doubt we could get away with another tall structure.