Yes you will need an alignment. As to what spacer "kit" to get, some is personal preference and a lot has to do with what year truck you have - the '97 and older ones are cheap and easy to lift and there is a wide variety of ways to lift them. The '98 and newer ones are not so cheap to lift and how you lift them depends a lot on what suspension type you have.
When I did lift spacers on my 89 Bronco II, I got the F-150 spring perches (IIRC there is a write-up in the tech library on doing it). I purposely avoided doing things like stacked washers or a lift spacer because I have had the truck on the road and in PA, according to the inspection book, you are not permitted to use lift spacers on the front. So by going with the spring perches (which accomplish the same thing), if anyone gave me a hard time I could point out that it is not a lift spacer but a spring perch.
But that's how my devious little mind works....
