I have a medically complex 5 year old. We've used Farrell/SAr Peds since she came home from the NICU. They were recommended by the neonatologist who delivered my daughter and I drove out to meet them before she was released.
Note that there are like 8-9 docs in the practice and in my experience the continuity of care is poor. My daughter's charts (she has 3 of them there) are inches thick. When we come for care, it's always very obvious that no one has taken the time to read any of the specialist reports that were sent. As far as blending alternative with conventional, I think the craziest thing they've accepted is recommending extra yogurt or a probiotic during antibiotic use. Honestly, I don't even tell them half of the things I do (I do, however, tell our specialists providing care).
I've heard way better things about Ashburn Peds. I've wanted to switch so many times in the last few years, but loosing all of the history stops me.
I think that the Farrell name is tossed out because the current doc took over the practices from his dad who probably 30 years ago was the big ped in town. All in all, I don't think you'll find what you are looking for with them.
Good luck.