For the purpose of PhD admission, take the university job. It gives you an opportunity to get a strong recommendation from a faculty (read http://www.gmatclub.com/phpbb/viewtopic.php?t=42808
If you have sufficient space in your SOP, you can describe how you turn down an offer for a "research associate job at a company that does i/o psychology research" for the one at the university because you are really passionate about academic research.
Note: I have nothing against working in the industry. I myself worked for 6 years in the industry and value the experience. Actually, for OB, a little working experience may be good and useful. However, if you are very focus on getting a PhD, it is best to stick closely to anything academic & research.