The city light uses a 4 or 5 watt bulb, such as Jahn 4088 5W or Osram T4W. I have a web page or two
here that shows how to wire them. Your city lights will be on when ever your front corners are on. I think there may be other ways to hook them up, if you have a non-USA car.
With the Bosch or Hella units, it is my understanding that you can use up to about 100 watt lights before needing relays and wiring. The stock wiring is absolutely adequate for the stock 55/60 watt H4s. I have no experience with the DEPO headlight units.
My web site has the info on how to hook up to the stock wiring harness and what parts are needed.
Hope this helps.