KW c500 double set back tandem tandem 8X8 help

[Jakyat]

I am now onto the lighting and I am turning to you guys for help. By the time its all said and done, there should be close to 30 leds running on 4 different channels. Im using 3 volt leds. I have purchased some receiver activated switches and will be using the x-plus module withmy dx 18 tx. Rather than trying to figure out which resistors i will need, I would like to supply the x-plus with its own power source to effectively power the leds without resistors. Doing it this way, I should be able to turn lights on and off with the toggle switches on my tx.
My problem is, I don't know how much power i need to feed the expansion module. Im looking for feedback from you guys. I don't have enough room to install a mfu.