Put a lockrite in your front Dana 30. Don't spend any money on the Dana 35, just leave it open. I ran a YJ like that for several years until I was ready to swap a Ford 8.8 in the rear.
If you are hell bent on spending money on a dana 35 locker I wouldn't do anything but put in an aussie or a lockright. You don't have to spend the money/time to reset up your gears because it just goes in place of your spider gears. They only cost about 2-300 dollars and you can easily resell it if/when you decide to upgrade.