DBT is supposed to be the best choice for people with BPD. If you can find a good DBT program in a group setting, those can be really good.
I also think mixing DBT with other therapies can be even more effective.
I also came across this one therapist in the UK who specializes in working with BPD clients. She does a mix of DBT, schema therapy, Jungian therapy, and some others. This is her website
Eggshell Therapy and Coaching