Dry tongue weight listed on a 2012 A124 is 253 lbs....you didnt say what year your 4Runner is, but I would guess if you can only tow 5000 lbs, you have a V6 and a max tongue load of 400-500 lbs.
Dont count on that dry hitch weight as the actual weight you will be carrying....Tongue weight adds up pretty once the battery and propane are tacked on...You might consider a weight distributor if you add additional weight to the tongue if using a dual hitch to carry more stuff.
As Tom pointed out, there is plenty of room inside the trailer. The available space to carry inside is deceiving but once it gets packed up, you'll discover the pleasant surprise in how much stuff you are able to bring along.
2012 FR Flagstaff T12SDTH
1996 Shadowcruiser Pop Up Truck Camper
1967 Newell Motorcoach
2003 Ford F150 5.4 V8 Triton Super Cab
2004 Nissan Titan LE 5.6 V8 4x4 Crew Cab