With bias ply's and a stock ride height I wouldn't worry about the max caster install, you could just install them to lengthen the effective length of the arms.
If you did install radials I would probably do the max caster install, or maybe even split the difference by installing a stock bushing and an offset, ie, use an offset in the front leg of the UCA arm and a stock bushing in the rear. That would lengthen the arm slightly and give a small amount more caster adjustment. Typically you install the bushings like indicated in the picture below for max caster, so the front arm is effectively longer and the rear arm is effectively shorter, giving more caster. An offset in front and a stock bushing in the rear wouldn't shorten the rear arm, which would be better for you, but it would also only give half of the caster addition that using two offset bushings would give.
Also, something to consider would be using the later FMJ spindles. Those spindles are slightly taller, which would help compensate for the 1/2" drop on the K member. Not sure if you're using the BBP though, and of course the brakes would be different. Sounds like you're trying to be pretty accurate, and of course the later disks would be different.
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