Undercoat

Hi everyone.
Mr. novice here. I am going to have a lot of questions for the next year or so but I hope to have a nice 73 Challenger Rallye 4 speed w/ 340 on the road this time next year.
I have my car up on the rotisserie I built. I have taken off all the rubberised undercoating, sandblasted, sprayed some self etching shaker cans of self etching primer on the underside of the car to prevent any surface rust from forming. Patched the frame rails where needed to have some new metal welded in. Built my frame rail conctors and torque boxes that will be welded in after the car is back on it's wheels. The guy I bought the car from last summer already put in new floor pans.

Today's question is what should I use to put on the underbody of the car? I was thinking something called "chassie saver" by magnet paints.
Thanks for your help everyone!!!
Bill (Vermont.... the land of RUST!)
Happy Thanksgiving to everyone!
Author: Bill