One of the nice models from the Epic 40,000 era was the Deathstrike Missile Launcher.
This one shot super weapon was often at the heart of many an Imperial Guard Artillery Battery. This model is from Simon’s collection.
Unlike a lot of Imperial Guard Epic vehicles this one has never been made into a 40K version by Forge World, though this has not stopped others from scratch-building their own. Rules for the 40K version will be in the forthcoming Imperial Guard Codex. At the time of writing no details of any model has been released.
More photographs of Epic artillery.