Best bet would be to order the Warner Marine Phos-R from Premium Aquatics. It will get to you on Monday.
If you cannot wait, I have seen Phos-loc at Deep Reef in Downers Grove.
I have used: Rowa-phos, Phos-loc and Phos-ban. Of the 3 I prefer (and just re-loaded with) Rowa-Phos. If Premium had the Warner Marine stuff when I ordered last week I would have ordered that instead (this is what jdieck is using now and when it comes to reef chemicals - I listen to him).