So far, the biggest yielding one I've found is the Snowdawg line. One of our testers reported 10.7oz off one indoors, vegged for 60 days, and flowered in a 10 gallon smart pot. I'd say that's pretty decent.
As for potency, you would really need to refine your query. Do you prefer daytime smoke, creative smoke, or stony smoke? If you are going down the middle (THC), I'd say Eisbaer. If you are looking creative (CBN), I'd go Superbomb. And if it was nighttime smoke you're looking for (CBD) I'd hit up one of the Kushes. Hope that helps. I'm in a mad dash this week to get all our new packaging, designs, and promotionals done this week prior to the release of the new ones. Sorry for my absence everyone. I promise I will one day be able to take on an intern/new hire! One day...... *daydreams*