I'm going with a Tacoma and Fleet knowing that it will be overweight, but expecting it will handle it just fine with the mods I've planned. Sure I could go to a half ton but I'll be overweight by just as much in most cases, just have an overall heavier rig and not fit in the garage. I already did that once.
However I wouldn't even consider hanging a dirtbike off of the back with a camper on the Tacoma. The weight of the bike is going to end up being centered probably 5' behind the rear axle to clear the camper. You're shifting a lot of weight of the front of the truck and to the rear axle. Instead of just adding the camper to the rear axle, you're adding the weight of the hitch rack and the bike. Not just that, but you're likely taking 50% of that weight from the front axle (due to the leverage) and adding it to the rear axle. So you are likely adding say 450lbs to the rear axle with a 300lb bike/rack combo, on an already light truck frame. I don't want to hang anything off the back heavier than a dirtbike or two, personally. With a small trailer the tongue weight will be minimal. Easy to haul a bike (or a few), extra fuel, maybe a locking tool box for gear etc and get it out of the truck.
Two issues with air bags off road on a Tacoma. First, you're replacing the bump stops, and the aribags will not have internal bump stops. So if the truck is riding low or you're not aired up much, you will bottom out very hard and probably destroy the mounts and shear bolts to start. Secondly, unless you limit the rear axle droop or add a daystar cradle on the bottom, you'll be overextending the bags when the axle droops and tearing the bags apart. And a third I guess, if you're not also running heavy duty springs, you're placing a large load on the frame in a spot that isn't intended to. That probably isn't the end of the world, I just don't like it a lot. I have seen cracked frames around air bag mounts many times, although I can't recall if I've seen that on a Tacoma specifically.
I would suggest a heavy duty leaf spring setup as a base. If the camper will be on full time just consider a custom leaf spring pack and be done with it. If not, add either air bags or timbrens to the HD spring pack to help the load if needed. That's just my personal preference. I'm planning to run Old Man Emu springs, probably with their add-a-leaf installed and the bottom overload spring removed. It will provide 2.5-3" inches of lift over stock in that setup and a firm ride unloaded (fine for me). But it will have a high spring rate and carry a load well. I'll likely run taller, softer Timbrens to and set them up to engage after 1.5-2" of spring compression. This way the springs will carry most of the weight, and the Timbrens shouldn't be too rough. No restrictions on suspension droop this way except the shock, so I'll run longer than standard shocks and longer brake lines. Bottom outs shouldn't be an issue as the taller Timbrens have 2.75" from contact to full comression. I'm thinking that this will be a good compromise for what _I_ plan to do. I know I can play with the leafs by adding and removing, flipping overloads upside down etc and sort of tune the spring pack. The tricky part is making it "reasonable" unloaded but I'll likely keep my camper on most of the time.
I was planning on the OME leaf springs and airbags with cradles, but I'm concerned about the lack of bump stops. I'd really rather have the springs do most of the work and be able to haul down washboard and rough roads without worrying that I'm going to tear something up.
Also, definitely check out that thread on Phoenix campers. Yes they do some cool custom work. But I'd go for a solid FWC and enjoy your retirement instead of stress and worry and repairing stuff.