Guess it depends upon what you call a "huge" truck. There are many 3500/F350 SRW trucks capable of pulling many options of 5th wheels. There are versions of 5th wheels that lend themselves to fulltime living. Since the light weights have to cut weight somewhere, I personally would not look at a light weight camper for fulltime.
Full timers tend to add about 2,000# of stuff so add that to the empty weight of the camper. The pin weight will be about 20% of that, so as an example a 10,000# loaded trailer will have approximately 2,000# pin weight. This will allow you to roughly guess how much truck you need to tow it. You'll need enough truck cargo capacity for passengers, gear and pin weight. Example you have a 3,000# cargo capacity - 2,000# pin weight - 200# hitch = 800# for passengers and gear in truck. Best way to get cargo weight is to weight the truck and subtract that from the GVWR found on a sticker inside the driver's door. That's the basics to get you started.
Physically a 3500/F350 and 2500/F250 are the same size. They tend to sit about 2-3" taller than a 1500/F150 but body is pretty much the same. As a basic rule of thumb you'll be in the 2,500/F250 to 3500/F350 range with a 5th wheel. But that's a whole different thread that you can search on.