Welcome to IRV2 and as far as the tanks, if there are no stress cracks near the mounting rails, and no other obvious damage I say save the money for more important stuff, like upgrading the tank sensors to some thing like seelevel or at least horst tank probes. but just my opinion.
Again welcome to IRV2
Spencer & Tracie RVM#62
2013 RAM 3500DRW 4x4 Laramie, Cummins, 385HP,850FTLBS Aisin Trans
2014 DRV Elite Suite 41RESB4
Spare puller:2004 RAM3500DRW Cummins (DW's truck)