Not a comprehensive list by any means:
If you're looking at ADHD-like symptoms, the focus should be on executive functions. Common instruments would include DKEFS, Conners Rating Scales, BASC-2 rating scales, CBCL/Achenbach/ASEBA rating scales, BRIEF rating scales, DREF rating scales, Conners CPT (computer-administered direct assessment), Conners CATA (computer-administered direct assessment of auditory attention). WCST is an old favorite of neuropsychs. If administered a rating scale, it is likely that it would be just one of the menu listed above, and not all of them.
Memory instruments include the WRAML-2 or CMS. CVLT (verbal learning) is also a favorite for memory and learning.
Visual processing might include subtests from the Wechslers or some other standard battery intelligence test, BOT, Beery-Buktenica/VMI, RCFT (the Rey). Assorted finger-tapping tasks and peg board tasks also pop up here, in the visual-motor area.
A neuropsychologist may be more fluent in the neuropsych-specific assessments, as they likely do more of this type of assessment--and the ones you're looking at may have additional value if they actually are good at differential diagnosis between ADHD and look-alike disorders--but an educational psychologist is likely to be more in tune with recommendations with real-world school applications. Experience with the type of student being assessed is also quite important, as clinical skills are particularly important when interpreting assessment results for a 2e client, where global and composite scales often aren't good representations of their true learning profile.
And of course, it's quite important that the assessor be someone that you feel your child will feel comfortable with.
