Not seeing 800 HP in that combination with any of those heads.

If the Stage VIs are MW, I wouldn't rule out keeping them and building a better combination around them. I don't know what sort of bang-for-the-buck improvement you'll get going to the TF 270 or "super prep" Indy EZs.

You've got a lot of variables in play, so better be clear on your budget before you jump in. I could imagine it spiraling out of control quickly, depending on what parts choices you make. Too many unknowns to really take this much further right now.

So... what IS your budget?