Improved Clone

As you're probably aware, this conversion is aimed at ending mid-epic tier. I'm know, however, that many groups will want to continue on past that point, to greater things. In Sins of the Saviors, the party can recover information on the Improved Clone spell, allowing a spellcaster so inclined to spend a great deal of time researching and perfecting it until it was able to provide him with virtual immortality. This is a prime target for implementation as a ritual in 4e. Here's what I'm thinking:

First, Improved Clone would represent the upper end of what a ritual could do - in fact, immortality of some sort is an inherent part of each character's epic destiny. Improved Clone will therefore likely end up as a 30th level ritual.

Next, it will have a substantial cost, in components, time, and personal investiture. Obviously, this will be a monetarily expensive ritual. It needs to account for the game utility of essentially having a backup character in the event of an untimely demise - in many ways, it is far superior to the raise dead ritual. Time-wise, the ritual should take either a year and a day, or ten years and a day to successfully perform, with each passing day requiring a payment of healing surges to sustain its casting. All of these costs would need to be paid each time the ritual is performed; once the original body dies, it would be assumed as part of the ritual that the cloned character would forget the particulars of the ritual, and would need to spend the time and money associated with the ritual to become reacquainted with it.

Give me your thoughts on this ritual. What should be required to perform it? Should it have any side effects on the character? Because of the attractiveness of this ritual, it can have some significant hurdles or downsides, without dissuading players from pursuing it. How long should it take to sustain it to completion? Let's hear it!