Since you have a Ram, an easy option for an antenna mount is this bracket: FIRESTIK Dodge Ram Hood Mount with K-4 Stud, SS184 https://smile.amazon.com/dp/B000X3EQ1I/
Along with an antenna and coax of your choice. I'd recommend this antenna: Wilson 305-492 T2000 Series Black Mobile CB Trucker Antenna with 5-Inch Shaft https://smile.amazon.com/dp/B005AUONAS/
And rg8x coax similar to this: Astatic 302-10267 Gray 18' Mini 8 Coaxial Cable https://smile.amazon.com/dp/B000RG30CM/