I have aligned several vehicles the same way as you described by setting the lca on jackstands and making sure to keep the ride heights the same front and rear as they were with tires on the front, it seemed like it worked ok although I never had them rechecked with tires on and a better alignment setup. Another option you might try is to get a
Fasttrax alignment gauge they're not that expensive and you don't need turn tables or have the ground perfectly level, I have aligned several of my cars this way and had excellent results! Here's a short video of one being used, http://www.youtube.com/watch?v=ZwyfUXsXTV4&list=PL176CF5D77C6A3EC7