You can get away w/o UCAs, pretty sure quite a few guys run that way, if you haven't heard/felt CB contact, you will.
You can run stock shocks but they'll wear out quickly, it's better that you upgrade to longer shocks. I don't think you will have problems with brake lines but I think you'll need to unclip them at some points and allow them some "air".With a three inch lift in the rear, along with the spacers in the front, do you need to get new shocks and or brake lines?