Great news.. just contacted Carson Toyota and Paul 310-522-2300 the Parts Dept helped me out. The 2JZGTE valve springs are $4.17 each and they are sold individually. Total is $133.44 a set of 8. With oem 2JZ valve springs replacement. The 1UZ jump from 42 lbs spring load to 65 lbs spring load.
I know you have taken some initial measurements. http://www.lextreme.com/spring.html
Have you had a chance to look at what height both the springs bind at?
This might effect how much lift we could feasably run with these springs.
If these work I might know a source for the 2JZ springs w/ retainers at $2-3ea.
For FI engines the heavier spring tension will overcome some of the lost tension due to the pressure of the intake system. If you're running 20lb boost the back of the valves have 20lb pressure on them all the time. This means an 80lb spring only has 60lb of effective tension. 80 - 20 = 60.
The second for all engines is it will fend off valve float until higher revs. They can also help down low with steep cam ramps in keeping the valv in contact with the follower.