If you are going to convert anyway, you might have a look at the 1st edition Warhammer FRPG adventures "Shadows over Bögenhafen" and "Power behind the Throne."
SoB takes place in a mid-sized town where a rich merchant has become a pawn of a demon. The demon has tricked the merchant into performing a rather grisly ritual which should allow the merchant to reclaim his soul. Alas, when the ritual is successful a chaos gate is opened instead, which allows other demonic creatures access to the place. If the PCs are not successful, there'll be dire consequences for the world.
PbtT takes place in a big city (with some architectural curiosities) where a chaos cult works to bring down the whole city and a lot of powerful entities of the realm. This adventure is very heavy in the roleplaying department. If your players like to uncover a good story and deal with lots of colourful, well describes NSCs, PbtTis a hit.