I've experimented with a few varieties of lights and how well they work with pwm fading in particular. Take a look at this video here for more details:https://plus.google.com/102015744723309264957/posts/9D6koAM74ex
Main take-away I have at this point from my experience is that when plugging lights in at your normal house voltage (i.e. 120V AC in the U.S.), the incandescents tend to fade nicer with pwm - while the led light strands typically have a transformer or rectifier that makes pwm fade simply not work (looks more like flickering than fade). That said - you can change those to be on-off mode and the leds still look great.
So I guess the only real points I have to make are:
* Ensure each you don't overload your output relays (if using the SSR's on the sainsmart board, that limit is 2 amps per channel)
* Incandescents fade better than leds if you are switching AC voltage via SSRs / Relays (I'd like to work up a better hardware solution for leds to get around this - haven't had the time yet)
* Be creative - we'd love to hear what you experiment with and get working - let us know so we can all benefit! :-)