It appears your explanation cut off:
...can you please complete your thought?
Thank you so much for your help! Can I ask you a big favor and ask you to provide me a link to the exact hardware I need from a site like homedepot.com or lowes.com?
Based on your answer, I can take one of two routes. Find some 5 or 6" 10-24 screws to mount the fixture to my exisiting box or add an octagonal 1 1/2" deep extension box and connect to the exisiting box and fixture using the provided 8-32 3" screws.