For a someone that hasn't the desire to, or the experience in building a pair, buying a set would be easier. I have a set from pmf that I need to put on. I can't imagine building a set would be so much cheaper that one could justify it for the cost savings alone.
i got mine from topguncustomz, terrible customer service, but they are the pro-comp ones and they were at my door for 470, may not look as great as the others, but it gets the job done.