I'm sipping my next-to-last bottle of oatmeal stout.. extract kit from Midwest. It's pretty good. I aged it 6 months. It's a little on the weak side for ABV, I'd recommend bumping up the gravity with an extra pound of DME or LME. I used the WL Irish Ale yeast upgrade. It's a little sweet... perhaps it would be better to use the cheaper dry yeast that would attenuate a little higher.
Edit:
Then again... you want "creamy"... the sweetness definitely has a creamy effect, might be just what you want!