You can get up to 3" out of the FRLV front shocks. I've seen guys run the 39s but they were on 3" front collars and 2" rear spacers.Thanks for the response. Sounds like the FRLV fronts with stock rears is the way to go. You have any idea if the 39" KM3 will clear with roughly 2" front lift on a 9", +0 wheel? I assume I can get 2" out of the FRLV? Out back is there any reason to do a spring over a spacer if I'm not running a bed cage with dual spares? The rear will get a bedcover only, and will be used for luggage, etc.
For me, the rear option would depend on how high you end up needing to go in the front. Rear spacer options are 0.5", 0.75", 1", and 2". While you can also do Eibach springs at 1.5" so it gives you middle ground depending on how much rear lift you need.
If you're going for peak height up front to clear the 39s, I'd recommend upgrading UCAs with more flex as well. We did Foutz for a number of reasons, one of which is I like that they use a bigger uniball at the knuckle to maximize flex.