In my experience, reconstructors tended to be a little stronger. I really don't think it matters too much because both will add protein. In terms of protein strength in general, the darker, the funkier and the more liquid (in terms of creamy vs straight up liquid or gel), the stronger the protein content.
Not matter what you decide, follow with your protein treatments with a moisturizing conditioner. Some conditioners that are really mild proteins like ORS replenishing pack don't need to be followed with anything else.
Things like Nexxus emergencee, duo tex, Dudleys DRC, Aphogee treatment for damaged hair and other strong proteins like that need to be followed up all with moisture