It's hard to test for movement in the link while the beast is up on jacks as you need a load or weight baring down on the suspension. There's a 98% chance that the sway bar links are the culprit. Given that probability with the cost (40-70 bucks for the pair), and the great DYI write-up, I'd just replace them. Worst case scenario, you'd have new links (which would have eventually failed given the written track record). My 2 cents (which cost the government about 10 cents to manufacture).