Urgent! 1993 Honda Prelude Fuel Line Size? HELP!?

My friend developed a severe gas leak from his fuel lines. We have someone that will repair it, and someone who knows what their doing. He doesn't know what size to buy (He was told 3/8ths would work by the guy who knew roughly what he was doing -- but the guy wasn't sure). Is 3/8ths correct, or should he get a bigger size, or..? We aren't very car savvy people, so please help!