I will be running 2 roof mount scrrens, 8 inch both which have twin dome lights, a 7 inch motorised screen in the dash and a JVC dvd unit. Considering there is 3 screens running ay once will a normal battery setup suffice, im ean when its hot and running aircon and all the other electrics at the same time?

im running four gauge for the amps, alpine sub and rear 6x 9's as well. the battery is basically the heaviest duty one you can get BUT its the RACV ones LOL. Question is, is it better to buy a split battery system and run an isolator switch or one of those optima red cells? Help need as i dont want to melt my electrics and draw too much currect so that every time my car battery is flat.