Quote Originally Posted by exelanoz View Post
Can anyone suggest or guide me in the right direction for the right type of switching device?
I'm using IRF9Z24N P-channel MOSFETs to drive LEDs at 3Khz PWM. I'm driving the P-channel gate with a 2N7000 N- type under PIC control because that seems to work the best. As a test awhile back, I took 6 of these, paralleled them (because I've got 3 on each board, RGB setup, see www.srt.com/~jdgrotte/kromatoobz.htm), and used them as a starter motor relay. The traces on the PCB let loose before the MOSFETs did...but I was just screwing around, trying to blow something up!
I'm sure if you could find the N-channel equivalent, you'd be in good shape.

I could go on, but I'd just be repeating what rmteo said...
Low Rds(on) at a low Vgs with a high Id is what you want.
In general...
The lower the Rds, the less heat the package dissipates at a given current across the drain-source.
The lower the Vgs, the lower the voltage you can put on the gate and still have the drain-source conduct a decent amount of current.
The higher the Id, the more it will conduct at a given Vgs.

Read up on your MOSFETs in wikipedia or something and you'll easily see why MOSFETs are almost always better than standard ol' transistors in this sort of application.