Did you draw up a business plan yet, and give yourself a resume of sorts to compare your background and skill set with other DJ's who are currently dominating the circuit?  It should give you an idea of what you really need to have.  Also its who you know, if your not at the club meeting the right people than yeah its nearly impossible.  There isn't a magic agency out there, its like the NBA those places are looking for rising talent or an excellent resume.  Thus, why local residencies are so important if that is your goal.  Kaskade started playing out venues that fit 200 people and were 1/3 full.  He plays about 150 times a year currently.  It wouldn't hurt to contact an agency and ask them what they really look for in joining their roster, might give you something to shot for.