You probably don't like the results of Photoshop's default behaviour on grayscale conversion because it does a straight value map with no toning involved. One of the most powerful and overlooked tools in the software is the Gradient map.
You can use it as a sort of super curves adjustment. Create a gray-scale map with Black on one end and white on the other, and you can tweak the midpoint, add additional positions and generally achieve any effect a plug-in offers you for toning. Changing the light or dark values will let you tone an image in sepias or blues or whatever you like. Then save as a CMYK and you're golden. Just remember that with ink coverage limits on press you won't get 100% K, so photoshop will back that up with process colours at, usually, C75 M68 Y67 K90, or thereabouts. You'll have to tweak for your conditions if you want otherwise.
If you do it as an action with a user-adjustment stop inserted to tweak the gradiant along the way, you won't quite be batching but you'll be able to get the look you want without having to do more than adjust a slider per image.