Easy Fan Replacement

I have read multiple posts on this forum about upgrading the Fantastic Fan...but there are so many discussions that my eyes begin to glaze over after a while.
I know that (if I can find one) I can install an upgrade kit to my fan which will provide multiple speeds and a rain sensor.  But is there an upgrade out there that would replace the entire fan (blade, motor, controls) without having to remove the flange from the top of the T@B?  I apologize if this has bee covered before.  I don't mind doing the work, but I fear denting and/or compromising the roof.  Thank you in advance.