Hi Bullygirl800 and family,
Welcome to the forum. It will be a great family activity to
build your own and then go camping in it. I think it is fantastic
that your son is so enthusiastic about your build. It'd be hard to
think of a better bonding collaboration. He'll remember it his
entire life.
As was recommended by another, and I concur, I think you'd be
better served by returning the HF trailer and get an old popup
tent trailer that's past its prime [and in need of new canvas] and
use that as the 'donor' for your frame. That is a very common strategy
on here and you can find them for very reasonable prices if you
look around. Craigs List and such sites seem to be good sources.
Most are sized ~ 6x10 anyway. And, depending on its condition, you
may be able to use a lot of its components for your build. Go through
the Build Journal section, and you will find plenty of builds based
on the popup tent trailer frame. Of course, you'd need to probably
get a new axle [one with brakes is highly recommended], but you'd
most likely need to do that anyway with the HF frame for the size
you want to build.
Have you decided on strictly a TD ? or a Slouchy ? or a TTT ? For the
room you sound like you want/need, and your desired size, you could
do a combination of all three, that'd look like a TD but have the
additional room of a Slouchy or TTT. Here's some pics of a 7wide that
could be done as a 6w easily.



And here's a link to a nice close to garagable height Standy that may be
helpful to you:
viewtopic.php?f=50&t=29603&hilit=the+scenic+IIHere's a nice smaller standy build:
viewtopic.php?f=50&t=38663Here's a nice 'larger' sized nontraditional TD build from an Australian
forum member: The 12-04-11 post of his at the top of pg2 has its dimensions:
http://tnttt.com/viewtopic.php?f=50&t=47214Have fun planning, then building.
Cheers,
Norm/mezmo
If you have a house - you have a hobby.