ShadowProtect usually works fine with disk encryption. If you back up your drive from within Windows, the volume will be captured in its clear-text (unencrypted) state. When restoring this backup image, you will want to restore the original Windows XP MBR rather than the one from the image file, since the one from the image file contains disk encryption code (and the data is not encrypted). After this restore you would need to re-encrypt the drive if you want to continue using the encryption. HIR restores (to new hardware) should work with this method.
If you back up your drive while booted to the ShadowProtect Recovery CD, the data is being captured in its encrypted state. When restoring this backup image, you will want to restore the MBR from the image file and the Hidden Disk Track, since they both contain encryption code that will allow you to access the encrypted data you just restored. The downside of this method, as you mentioned, is that you could not use this image for deployment to different hardware, since HIR could not run against the encrypted volume.
Anyway, I haven't tried Bit Locker myself, but if there was going to be a problem it would most likely be with restoring encrypted data (as in Method 2 above). We have seen problems with a couple of encryption products, but many seem to work. If you do any experimenting with it, please feel free to post the results.