Dual tank kit

[Will B]

Hey first time poster here on this site. Hoping I can get some help. Looking to add dual tanks to my 83K20. Does anyone sell a complete kit that would have everything I need from the transfer switch and wiring harness out to the straps and tanks? Next question is how hard is it to wiring in the switch in the cab? Wiring isn't my strong point by any means.

Here is a pic of the truck. Pulling the flat bed off and putting a regular 8ft bed on it.