Converting a MR-01 to a MR-015 or MR-02?

[S2k Racer]

I recently got my first Mini-z (MR-01) And I was thinking of converting it to a MR-015 or MR-02 and I'm wondering,
Which would be a better conversion?
What would need to be done in terms of electronics and chassis?
What would the change to electronics do?
What would the change to the chassis do?

XD That seems like alot of questions.