Under belly protection

I am planning amung other things on a list a mile long I have , to start armer plating my undercariage. Metal is relitivly cheap and I only want to smooth out my underbelly to lightly scrape my way over the occasional object when my eyes are too big for my lift. Has anyone gone aead and made their own full or partial underbelly? Any ideas on thickness of metal. I want to protect just enough but I want to stay as light as I can. Float like butterfly sting like a... 'll I dunno. I want to stay light OKAY!! I am writing as I think here folks, so hit me with any of your best info. I have access to all kinds of tools and use them on a regular basis, so welding and fabrication is a fun side of the process for me. It makes me proud. DRIVE IT LIKE YOU STOLE IT!!!