As far as clothes, I think Marmot or Patagonia (not sure which, anymore) might offer pants and jackets with longer and shorter arm/leg lengths (I seem to remember ordering "short" rain pants from one of them.)

As far as tents, have you looked at the MSR Hubba/Carbon Reflex? They offer a symmetrical "half-moon" shape, with the entrance in the long side, and a 7-plus foot length with 37" of height in the middle of the arc - this might allow you to sit in the middle of the tent and follow the arc as you lie down. (I'm only 6 feet tall, and that's exactly why I ended up choosing a Carbon Reflex, after trying out a number of tents.)

I think the reason it's tough to find stuff is that you don't fit the bell curve: all the "regular" people make up the mass market, which is where the mainline manufacturers have to target in order to make money. (Whether profit is a dirty word is another argument; the fact is that it drives gear availability.) So, the tall folks and us folks with stubby little legs (and a 29" inseam) tend to be the outliers that have trouble finding stuff that fits right.

It might get a bit pricey, but your best bet might be the small gear makers, like Mountain Laurel Designs or Six Moon Designs. Since they don't always manufacture in large runs, they may be able to accomodate your needs and customize their designs to fit.