Which solution is best

Flexi pipe on my vehicle has split resulting in no back pressure.
I have two brother in-laws telling me two different ways to fix it.
First who owns nice sports cars and has never failed an mot as he just keeps his cars that well maintained and does all work himself says it is just a case of buying the whole front pipe/down-pipe and just quickly swap them it will take him ten minutes he said.
The other in-law a boy racer who knows his way around a car but always has a naft car coz sommink broke or going on it. He says I cannot buy just that part even though I have shown him the part online he says I will have to get the catalytic converter as well and it will cost me a bomb. So he says just to buy the actual flexi part and get a garage to remove old and weld the new on.
I guess both would work, but I am new to cars so I would not know who is giving the best advice. Any help would be appreciated.