LT 3080/3092 LDO

The Linear LT3080 is a 1 amp plus LDO adaptable to a constant current source.
The LT 3092 is a version of it set up as a current source for devices like LEDs.

http://cds.linear.com/docs/Datasheet/3080fa.pdf

It requires only one capacitor and two or three resistors for the circuit.
The circuit may be limited to 200 ma in the application of it as a power current source. That's a little low. But there are ways of getting it to play at a higher current. The simplest way is to use a shunt that provides another 200 ma or so around it. The regulator can adjust total current, while it doesn't need to source or sink the total current.

For real simplicity, and with a regulated 15 volt supply available...
Putting a resistor in series with the lamps makes good sense. A 5 watt resistor will work well. A 50 ohm resistor would pass under 300 ma. Raw empiricism may be needed to select the correct resistor value.