Phatmike10, When you say take out one rod to make it lighter, do you mean one of the carbon rods that go end to end? That would reduce the weight by next to nothing but take away much of the stiffness. If you mean the tuners, the bits with holes that the rods run through, you could take one out and reduce weight, but they are not that heavy so I don't think the change would be all that beneficial. The really long ones, with four tuners, are a bit heavier than the shorter ones with three tuners. That's to be expected, but the extra weight is not that great, it is the extra forward balance that is most noticeable.
The safest option is to try them all.
If Beiter is the thing for you; you could get the longest one and move the weights closer to the bow, a little at a time, until you get what you want;what feels right and gives best results.
You could try one, like the 30",and if it is not giving enough forward balance, add weight on the end until you get what you want. Or add an extender.You could move the tuners nearer the bow if it gave too much forward balance, but I think that is unlikely.
I put the three options in order according to the way I operate. I would have to try them all.Not just Beiter.
If the trial was not an option, I would enjoy trying the longest and seeing what I could get out of it with some experimenting. I like experimenting.
Getting the 30" and adding weights or extenders is perhaps the option for someone who doesn't want to experiment too much, so you can use standard parts in different combinations.