My suggestion is forget the subpanel, go ahead and use the money for leds... You will save so much money over time its not even funny... 1st your electric bill will be less, you dont have to worry about heat sinks ever again, you dont need as many extension cords because you can have 10 strands hooked together, you wont need as many channels because you can have more than 3 strands of lights on each channel, you wont have to replace lights every two years because they last longer, your show will be twice as bright, best of all, leds dont fade. I had blue incadescent lights last year and they were completely faded by week 3 of my show... Not going through that again. Anyways, just an opinion...
Congrats on the baby, my wife is due middle of October, so I am trying to build a setup that will allow me to put over 50,000 lights up in two days. The wireless is going to really help me out with this. I am going to have around 14 expresses, and 16 other devices all on wireless. I have built all my boards and 4 of my rx wireless devices. I have ordered the parts for 14 more and as soon as RJ releases the next batch of wireless boards I will be soldiering late into the morning. Not sure if you saw my video or not, but I would make as much as your show modular so that you can just set things out and be done with it... With wireless, its plug and play.
Sloan