Hmm... I don't think there has every been a 35 scale as standard for any model. So we're probably talking about going from a 34 to less. Without ever having played the shorter scales(!), based on what I've read here I would be fairly confident of getting a good low B on a 32, neck through, with ebony lams (or maybe purpleheart), but I would be skeptical about 30.75.
As Bob says, horn length is really important, as well as how close the bridge is to the end of the body. If you get these things right, you can easily bring in those low frets by a couple of inches.
But as for tension, I'm not quite sure I agree with Bob's suggestion. Maybe the technique would yield a fair approximation, I just don't understand the math in this case. Presumably, you would be buying strings for a shorter scale length, and they might well be designed for a different tension.
What is your right hand technique? If you're mostly a finger plucker, then I think you can afford to slide the bass right at least six inches, and maybe more is better. That brings the low frets within easier reach, and (for me at least) makes your right hand more comfortable, and also compensates nicely for the difference in length between your first two fingers.
So you might consider an unusual strap configuration to help bring things in reach, and pick or specify a body style that has the bridge relatively close to the end of the body, with a fairly long horn. You can also get the end of the neck closer by wearing the body low, with more angle on the neck, but again this depends on your style and what feels comfortable.
-Bob