Generally speaking, I think that you get about 1.5-1.75" of lift, you also have to take into account the fact that there are circular grooves (if you will) on each side of the spacer that help seat it between the spring and the isolater, which are I belielve about 1/8-1/4" deep--at least this was the case of my cheapo spacers from eBay. Also, you have to take into account how old your front springs are, if they don't have enough 'boing' in them to extend your shocks out there will be some limitation there.
Secondly shackle wise, thats also a little dependent on springs (leaves). Saggy leaf springs will result in a fairly flat shackle--the newer your leaves are the more they resist being in that shackle and push away from it, leaving you with more upright shackle, and thus more lift. On shackles I would say that you really only get half the amount of lift advertised, they only mount to one side of the leaf springs.
Finally, as far as alignment goes, being as you're only looking for, and may not even get, 2" of lift, I'd say after you install it drive around--there shouldn't be too much/if any alignment change noticable. Especially if you don't put that many miles on it, I'd say let the Jeep 'simmer down' a little, that way when you take it in to get aligned, it'll be pretty much sitting where it will stay. By putting those coil spacers in, you'll be pulling the front axle back just a bit, so it shouldn't be too bad at all. I'm not saying don't worry about alignment, but I think it can wait for a little break-in.
Again this is all coming from me--whos gone down (and still has) the buget lift path--but my Jeep's also an 84 with a few miles on it. I'm no expert, and would recommend a second opinion, but hopefully that'll help you out a little bit.
Ed