As much as I miss my larger-than-life Minx, I would never want to put another piggy through the pain she had from her very unusual composite bladder stones - and they were not just down to a bad diet in the days before we knew more.

Those three years with her have been a magic time in my life and will always treasure them as one of the best things that have happened to me in my life!
A clone is NOT the same piggy as the one you have lost. It is a completely new being with its own personality, completely new bond and different journey. Personally I would find it dangerous to put unrealistic expectations on a poor animal that has no chance of never fully living up to them. It is in many ways a cheat on yourself at the price of a hapless pet's life.
To narrow your sight to just one 'special' piggy means that you miss out on other differently special piggies and on losing out on growing emotionally yourself.
Grieving is not just a negative experience; it can make us more understanding of other people's loss and suffering and it enhances our maturity and emotional intelligence. Working through the whole process and coming out the other side stronger is an important experience.
Loss of a beloved pet is also often the only way you encounter death in your life and allows you to learn coping strategies before you are confronted with losses amongst family or friends. There is no culture of death anymore in our current society; most people die tucked away in hospitals, homes and hospices away from the public eye. They usually do not just fall gently asleep in their forever sleep; it is often more physical than that. I must admit that my hands-on experience with with dying guinea pigs has greatly helped me when sitting with my dying mother-in-law during the last days of her life.