Firstly, you need your commercial ticket even if you're flying "for free." Your private only allows flights that are incidental to your business (e.g. you're a lawyer and you're flying to a client). Nothing where the flight is the primary endeavor is allowed. Further, the FAA considers flight time to be compensation, so unless you're paying your pro rata share of the flight expenses, you're being compensated, ergo, working commercially.
If you want to fly as a job, you must get your commercial. If you're getting your commercial, you might as well get your instrument along the way, as you're going to need 250 TT (if you go to a Part 61 training location), anyway. Plus, your instrument ticket is needed for most jobs, even primarily VFR ones.
Once you have your commercial/instrument ticket and 250 hours, you can get a multi add-on and start throwing out resumes--a couple regionals' minimums are still down there. Beyond that, you're going to need to build some time to meet the insurance minimums for most companies. Banner towing, surveying and pipeline patrol tend to have the lowest minimums, but even they generally don't get below 300 TT and are often around 500 TT.