Which electrics kit for towing - C4 Picasso ?

I am getting a tow bar fitted to my C4 Picasso, many differing opinions as to which electrics kit I should get fitted. Most people say get a Bypass kit, but just spoke to one mechanic who said a Bypass kit would burn the alternator and I should have a dedicated electrics kit. Help, will a Bypass Kit do the job without killing my car, only towing a trailer tent!
Thanks.