I don't know that a 4H bumper pull is all that much worse than a 3H bumper pull.  Especially if you can find some newer aluminum trailers. Your total weight might not be much different. Compare the weight and see just how much harder your truck would have to work.

I haul 4-5 horses most of the time. ( I have 5 daughters) Most are grown up now and only occassionally return home for a ride with dad.  So more often than not, Its me with a friend or one daughter and several of her friends.  And it has become increasingly rare to get my kids to go on any camping adventures because of their jobs, school and friends.  So mostly for the kids its afternoon or saturday rides. Any real camping is me and friends.

I do use a GN trailer. I had a LQ a few years back in hopes of the extra creature comforts getting my wife to come along and keeping my daughters interested.  But I quickly found it didn't make much difference, So I sold the LQ and replaced it with a Dressing room only trailer that I can rough it in. It's cheaper, lighter and I can squeeze that 5th horse in if I need an extra pack animal.

I find that I have more horses than riders now days, So I more often pack one or two extra horses and leave the trailer at the trail head and camp some where more remote.  This allows me to get all my horses exercised, I don't have to worry about who will feed and care for any that I leave home. With the extra horses, I can bring in lots of extras and niceties for the camping. And I typically don't have to deal with somebody in the camp ground running their generator all night.

My advice is:  Your kids are growing up, Do what you need to do to haul enough horses to keep them interested and enjoying what you do. Other wise the kids will find there own activities and you will be riding alone.

A camper and BP trailer have some advantages over a GN trailer; more maneuverability, better ground clearance on rough roads and  less of a chance for bottom damage. The camper can be used alone if you're sight seeing, and is easy to park in congested areas. If hard to access areas are your choice, this outfit may be the way to continue.

However, if your travels are open roads or occassional BLM paths, a GN has many advantages: less combined weight, much less hook up/loading times and efforts, more towing stability, less wind interreaction, better mileage, less bed weight on the truck and all your gear is in one place.

A 4H BP trailer is large and long, and when fully loaded, will have a high combined weight. If your camper is much longer than your bed, you may need a hitch or tongue extension, which adds even more weight to an over loaded rear axle and suspension. When you add this to your substantial camper's toll, your truck may be severely taxed and incapable of performing safetly.

Over the years we've owned several camper/trailer rigs, and now own GN trailers. With a Gn you give up the ease of the stand alone camper. Some people do use GNs occasionally only for camping, but they end up dragging along many extra feet of space that isn't being used. Parking is more difficult and frequently you will be restricted to only using designated camping areas with the tag alongs.

What you gain with a GN is towing stability and ease, a truck that isn't overloaded in the rear, and better fuel economy. Your overall weights will be less, and your truck will have a much easier go. The LQs are available in many lengths, the longer ones may over burden your truck. Unlike your heavy camper, the trailer weights are distributed between the truck and the trailer axles, with only about 25%- 35% of the total weigh being on your truck.

 You may end up with less living amenity space, in exchange for safer trips and less mechanical problems. We sold our last camper several years ago, and have completely switched to the LQ trailers, whilst not looking back at all. The convenience and ease of towing/loading is so much easier with just one unit with which to maintain. I can easily hook up by myself in a few minutes. With a camper and trailer, this process took two people and almost half an hour. Once I almost dumped a camper when I hit one of the jacks, when backing underneath. I'm greateful those days are past.

With a 30" hitch extension, and adding another additional 1000#s to it, you're inviting an accident waiting to happen. You will further decrease your truck's stability, and overweight its suspension. In an emergency braking situation, the hitch extension will compound the tail wagging the dog affect.

Keep the camper and use it alone. Buy a used GN with LQ. They're out there in that price range. Consider your family's safety first. You may well endanger it with a larger BP trailer.

Don't know anything about these but, here it is....

http://www.torklift.com/t.php?w_page=supertruss