need help with new steering column length

Trying to buy something similar to this: (floor shift with tilt)


I have a 87 Mazda b2000 standard cab, all new sheet metal firewall, using stock power steering pump, stock steering joints if need be, but I'm not sure what length of column to order and where to measure from?
Has anyone installed a steering column similar to this and what length did you buy?
The most common lengths seem to be 28, 30, 32, & 33"
What would be my best choice?

no idea what length you will need.

What mods are you going to do to make your tranny compatible with such a setup? You can always get an imported transmission because the ones for the Mazda Bongo used the column shifters. You should be able to find one of these stateside, I was able to find one for my swap.

what does my transmission have anything to do with my steering column?
Did a sbc 350 swap and have an automatic transmission(floor shift). i just wanna get a billet steering column and don't know what length people have gotten for their mazdas.