1. A neuropsychologist is first a psychologist...so you need a solid foundation in generalist training.
2. Gaining exposure through practica and mentorship is a very important aspect of neuropsychological training, so having access to faculty to actively practice (or who can provide access to active practice) is important.
3. Having a strong foundation in neuroscience is very important. If the program does not offer classes in neuroanatomy, neurophysiology, and simliar...can you take those classes throug another dept?
4. Publish and present. A good neuropsychologist has a strong background in research & statistics, so being able to show productivity is important. You can still very much be a clinician, but so much of neuropsychology is understand what data means, so you need to know much more about the assessment than a generalist.
As an aside....Generalist v. Specific Track is mostly marketing. A solid mentor will open far more doors than getting more classroom training or an extra practica in neuropsychological assessment. A quick search on here for "neuropsychology" or similar should reveal a plethora of threads about training and how to be competitive.