I like the idea of been able to use the main battery to power the MOSFET's and the lights. not to fussed if it slightly reduces the runtime

The main reson I plan not to use the ESC BEC is becaus my servo can draw up to 7amps and it cant supply that 1.5max, so ive fitted the Externail BEC and its set to output 6v to keep the servo nice & fast.

This is where is got a little lost
VCC power connection can range from 2.0 V to 5.5 V.
so i thought about using some LM7805 to keep it at 5v

this the the switch im thinking about using
[link]http://www.pololu.com/catalog/product/1210[/link]

Thanks heaps for the help so far, once completed im going to post it up with easy to follow directions to help out other peeps that want to have 2 sets of switchable lights