SAT prep providers in Northern VA

Hi folks
I searched the forums but Q&A for this query is quite dated. Wanted to request some updated insight into SAT prep providers for my son. Not really looking for private. Group lessons or classes is fine. Honors Prep came highly recommended but the founder is moving to CA and is now only doing private via Skype.
We are in Loudoun so something in this county is highly preferred though no issues in going to Fairfax if recommendations make it worthwhile. Please help. Thanks in advance!

-Deepster