I would strongly advise against operating the car without the upper torsion bar brace. It is imperative to handle the torsion bar forces. Hooker part number BHS578 is by far the simplest, cheapest, and best solution I have come across (and currently use).
I got everything from SST (except for the aforementioned part).
I also have a bench, and yes, the shifter in the rearmost position should clear the bench no problem.
Allow me to add my experience with the TKX swap and torsion bar brace removal. I was probably one of the first on this forum to swap out from a three speed auto to a TKX in my 72' Duster. My kit came from Silver Sport and I was very happy with the components. I had a local speed shop do all the work to my car.
When the shop did the installation they did not add a brace to the upper portion of the cross member that had to be cut away. I remember looking at the beefy lower support that was supplied by SS and thinking that "this looks like it should be able to handle the stresses of the torsion bars".
Since my car was completed, I put maybe two hundred miles or so on the car, driving pretty conservative as the clutch and new rear end I also had installed, needed to be broken in (although I did do one small burn out). The car handled fine and I didn't think anymore about the cross member, or lack thereof.
Shortly after the work was done I decided to sell the car. One of the last days I drove it, I noticed that the hood was sticking when I tried to open it. Now I don't know if that was connected in anyway to not having an upper crossmember anymore or not, but the hood had never had any issues before with sticking. I was hoping that the frame wasn't getting twisted out of shape or something.
If I were to ever do the same thing again (which I won't) I would definitely replace the upper cross member with something, more as a peace of mind than anything. All things considered, it's not an expensive "fix" considering the cost and time involved with everything else in a transmission swap procedure.
Pic of the lower cross member supplied by SS