If you do your rating on a 'light twin' (MEP Class Rating), then you will only be able to get a job with someone operating one of these types for aerial work. However most of these types (Baron, PA-23 etc) are used either for private flying or for schools.
If you do your rating on an aircraft that requires an individual type rating, then you will be better placed to get a job with someone operating that type, as they won't have to give you a conversion course.