I get my yogurts at Whole Foods or at our local nutrition/health store. I go to Cornerstone, which is out in Chesterfield Valley on Edison, right off of Long Road. I prefer a low fat yogurt (rather than non fat), but that's just me. Cornerstone stocks the Hemp Hearts too and truly I think they are the "guts" of this recipe - like if you only want to buy one thing. For those of you out of town, I would suggest you call around to health food shops and I bet someone has them in your area.
The Hemp Hearts are really tasty, at least I think so, but you may question my taste buds since I have admitted to enjoying pumpkin brownies. They taste sort of like lightly ground walnuts. Definitely a nutty flavor, good enough that you can grab a handful of them and eat them alone. They have high calories, so I measure to make sure I don't max out and fix a 1000 calorie yogurt treat, ha!
And finally, if you are at the nutrition store anyway, try CALM Plus Calcium. I have been taking one dose of this stuff every night before bed (I buy the flavored one so I don't have to mix it with juice). I swear it helps me "wind down" and have a good night's sleep. I've been sleeping better that I have in years since using this stuff. Now keep in mind it's not a sedative or sleeping pill - it just helps you chill. Plus it's got good stuff in it like Magnesium (which is good if you have migraines) and Calcium, which we all need.