If anyone of you all live in the Chicago area, we are starting up a yeast bank to trade yeast. Check out: http://yeast.cadwallion.com/ to sign up. It's free and there should be some good yeasts starting to fill up.
This sounds more like a process thing than a raw material issue. I sometimes shoot for a higher initial temp and let it come down to your desired mash temp over the course of 90 mins with a single temp mash config.