^These are great “options” , “if” you can find a new bed. And if you’re willing to toss a couple grand at a truck that isn’t worth much more than a couple grand.
IE not really practical if you’re limping along a 15 year old rust bucket.
If the bed floor isn’t rotted out, your handy husband can make some bed mounts out of tubing, hard rubber, stacked plates, run the bolts back thru or put in new location.
Otherwise toss the camper on, go for a drive and see how it handles.
Guess, if you have bed mounted tie downs I’d want the new mounts to be solid. Frame mount tie downs and not a big a concern. Bed floor only has to hold up the camper, not keep the whole mess attached to the truck.
No one here can predict how bad the truck is rusted out, but from your description, it sounds like it’s very rusted out.