CamCorder Housing and Light

hello,

I know pretty well uw digital photography and would like to buy a camcorder.

it must have a good quality but in a reasonable budget, because my specialization will always be uw photo.

apart from an housing, am I obliged to buy also a light?

I wanted to choose between canon and panasonic,which have a better relationship between price and quality, eventually sony but it's generally too expensive.

which model of camcorder would you suggest?

as for the housing, I know how to find it.

as for the light, is it necessary?

if yes, which model could I use for my pourposes (good but with a reasonable price)?

thanks a lot!

emidio, italy