Not to encourage the deviation idea, but I do believe my SPG hose is shorter than standard. I dive a short plate and it was recommended by a gue instructor that I get a shorter SPG hose. I'll measure it this weekend. I don't know why the tanks would be positioned anywhere other than the break, however.
On another note... There ARE a few cave systems out there that can beat the heck out of your gear, regardless of the quality of it (caves for which buying "nice" is no protection against failure!).
Just a couple of thoughts as I drink my coffee before heading to work on freezing cold Thursday!