Custom message / extra post in all threads?

[Host Directory]

Does anyone know how i might do this?

I would like to place a custom post in all threads to appear somewhere in the thread ramdomely.

I would need to be able to have a control panel with lets me choose which forums / threads i wish to do this to and be able to put custom html inside the post. Inside the control panel i would also be able to select a custom avatar and title for the post.
I would be able to set up as many different posts in different forums and threads as i wished.

So for example i could put one in all the forum posts inside the "Computer forums" if i choose. I could make this with a computer avatar and title such as "Latest news" inside the post i could place custom html and call some new news storys about computers.
Or any other html i wished.

So this would then appear ramdonlely once throughout all the thread post of all the threads in the computer forums section.

At the same time i could set up something different in another forum on the board.

I would also like the option to ramdomise the posts assigned to the same forums or threads.. so i could have several messages in the posts changing ramdomely.

I have limited funds but would pay someone if the right price was given.
Anyone up for the challenge?