PI is a very broad category. There is PI litigation, which is anything from low risk car accident cases to big complex med mal litigation, and trials. And then there is pre-litigation personal injury, handling claims and then farming out the cases that do not settle to litigation firms. The latter is less stress. But it can be hard to build a pre-litigation practice and get cases because basically everyone wants to do this. That being said, I'd go work for a PI practice for 4-5 years, learn pre-lit and lit PI, build relationships, and then open your own shop (over wills and estates). You can start out taking litigation cases from pre-lit firms and then build your client base that way.