I'm not aware of any available "on the ground". Walgreens has one on their website, but it's not sold in their stores. This is the link for the unscented version (they also have citrus thyme scent):(seed)**grape seed enriched conditioning hair shampoo bar | Walgreens
The poo bars I have used (Bobeam and Chagrin Valley) do not contain any chelating agents. You'd probably have to use a liquid shampoo specifically designed for that purpose, such as Pureology Purify. Bobeam does sell clarifying bars, however, if that would suffice. I have the Rootz and the Honey Hemp & Green Tea formulas in my rotation, and I'm quite happy with the results.
The CV bars lather quite well, and leave my 2c/3a hair feeling clean but not stripped. I alternate with low-poos, and have not experienced any problems with buildup after 6 months of use.
Many of the bars contain shea butter and/or castor oil, so if your hair doesn't respond well to either of those, you'll want to exercise particular caution. As with any product, it's a good idea to read the ingredients.
If you have hard water, as I do here in FL, you'll want to do an apple cider vinegar (ACV) rinse to restore your hair's pH, since the bars are alkaline. There's several articles and threads on ACV, including these:
Do a Hair Rinse With Apple Cider & Vinegar
TartNTangy, co-washing was an epic fail for me. I tried all the recommended conditioners, to no avail. It took some experimentation to find the right bars, but once I did, they were MUCH more effective for me.
The particular bar you've chosen gets very good reviews. Be aware that it tends to leave a dark brown tint on hair, in case that's something you're looking to avoid. (I've got the auburn and chestnut henna bars sitting in my cart for 3 weeks, waiting for me to work up the courage to take the leap!)
CV has sample sizes of all their varieties, so you can figure out which ones suit you best without breaking the bank