I used a 14M2 to build my own RGB strip controller. Your application (atleast with the LED strip), would be very similar with the addition of an additional channel for your 4th strip of white LEDs. Here's a schematic and PCB I made:I had imagined using a couple pins of the picaxe to control different sections of the stip, this one you can cut every 3. so lets say 4 channel's of 12 leds.
There are also 4 automotive lamps.
I am working on using a 4401 with a relay right now, but so far im all over the place with this one so that idea might change.
I thought about using a MOSFET but expensive device for multiple channels, and I have lots of smaller transistors laying around.
Thanks for the input