ORIGINAL: lupy
ham license is strictly a tx power thing, as reception distance is controlled by rx antenna. There's a test from a set of questions. Do a google search, there's plenty of info.
I suspect that the 500mw 2.4ghx tx set is lighter than the 100mw 900mw tx set or at worst about the same, because you only need a two cell battery, rather than a three cell battery.
Any plane you fly with a camera should be powered with lipoly cells to off set the extra weight and give decent flight times. Also look at a brushless power setup, as it will help too. A speed 400 power zagi should fly fine with a 3 cell 2ah pack.
Lipolys take at least one hour to fully charge, any faster and you will hurt them, you need a special charger, there are a lot out there now.
If you are worried about cost, get the kx 131, it's a great camera.
I'm assuming the idea of having seperate batteries for the TX and the plane's receiver is good practice too? Your saying that with my 400 speed motor and 15 ESC, I could simply add the lipo battery source? I've seen some who have said this, but yet others who have said I could burn the motor out, or it would be underpowered. I guess just switching to the Mega motor might be a good idea then? Would I need an ESC rated for Lipos (some have said my 15 amp ESC would be enough).. so I'm alittle confused on this one. Some have even said that if I switch to say, a bigger motor, or the Mega.. I could then still use my 1700mah NIcad power packs as well, with a different prop and maybe a different ESC.