I must appreciate your resolve to quit substances altogether. I am sure you have come to this decision after experiencing the ill effects of using them.
Electronic cigarettes vapourize a small amount of nicotine
along with other flavours & additives. They do not have the tar content of real cigarettes and are probably safer for your lungs. However, even nicotine and the other components of e-cigarettes have their own list of medical problems and must be eventually stopped.
Electronic cigarettes do not vapourize the metallic parts and do not give a metallic taste
as a side effect - especially a lingering metallic taste all day long. However, any of the addictives in an e-cigarette can give rise to such problems.
You may consider alternative methods of nicotine replacement such as gums or lozenges as available in your country.