As an RP Mod stated in another thread to you, now that it's known what your intentions are, you won't have much success. Even if you obtain some other user's account, your special bio request will more than likely be denied; because, for reasons I will not divulge, they will know it's you. I guess just from my life experience in general I saw straight through this thread: you don't intend to give up your account, you want someone's account.
The other thing that was reiterated to you in that same thread is that for RP purposes, it's not just how many posts you have, but what those posts consist of. I have nearly 13k posts, but not enough of them are RP related and so chances are, I wouldn't be given permission to use a special bio either because my knowledge and experience of the RP is lacking.
So not only do you need to find an account with the right amount of posts, that account would have to be an RPers account; which means they already have a reputation of sorts and when you suddenly are in control and have no idea wtf you are even doing, they will see right through you. However, you are already at a severe disadvantage because the RP staff already know you are trying to game the system due to your extremely less than clever posts.
Your best option is to go and RP as much as you can until you achieve the proper amount of posts, knowledge, patience, and maturity to have a Minato bio. I never was RP staff but even I can tell you that you won't earn that bio for quite some time. :/