an oft-quoted towing rule is the 80% rule.
it's a ballpark number to work with. it will account for passengers and cargo in the tow vehicle.
so, since your 4-runner's towing capacity is 5000lbs., that would mean a trailer with a max of 4000lbs.
having only a 5000lbs. towing capacity limits your options, as far as travel trailers.
i would look at the Mini-Lite or Micro-Lite lines for your Toyota. these will be within range of your v-6 vehicle.
how many will be staying in the trailer?
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC