Princess auto - GE5191-DPDT G.E. Time switch. 19.99 for the SPDT, 25 for the DPDT (go for the DPDT - to toggle 12/24v moonlights etc)
30A loads, DPDT, easily wired so as to turn on/off ancillary devices as lights go on/off.
Little bit of wiring involved, but they come in a big waterproof housing, and the wirings really not that bad.
Linky (no association, never heard of this company - just have pics/specs)
http://www.skycraftsurplus.com/index...ROD&ProdID=789