Alright, so I could not find a data source (that was open) for the specific request I made. That said, I'll go ahead and post links to resources I already knew of and additionally those I found in my search for the data requested above. If anyone sees this post and knows of a lead, please feel free to edit this answer or add your own post.
St. Louis Federal Reserve's FRED (Federal Reserve Economic Database) - good for general macroeconomic indicators and statistics, good coverage of specific industries as well (but still purely macro, non-institution/agent specific). FRED pulls much of its data from the various gov't agencies out there, like the BLS.
Data.gov is a repository for a bunch of random data sets the US gov't releases to the public. Searching can be a nightmare, and it doesn't include all databases (like FRED).
FDIC.gov was the resource that helped me the most. They publish total asset data and various other accounting measures for all insured banks in the US. Navigation can be tricky, but know the data is there.
SEC.gov offers EDGAR, a resource almost like FRED but for for financial data. Their resources (seem to) cover more nuanced accounting measures that the FDIC data, so it would help analyzing corporate behavior and structure.
The Federal Financial Institutions Examination Council offers a database with their Uniform Bank Performance Reports. The system seems fairly archaic but does work.
The EU offers an Open Data Portal, which is similar to the US govt's resource I listed above. It also has the same problems as the US version, but does allow for easier search refinement.
The EU central bank offers a Statistical Data Warehouse, which is similar to FRED, but it is not nearly as refined.
The ECB also offers AnaCredit, a database on bank loans taken by individuals and organizations.
the European Securities and Market Authority offers some resources similar to the SEC, none (that I was interested in) which I could get to work.
IMF offers data on the financial sector, from an (obviously) global and development viewpoint. I did not explore this system, but it seemed that there were a lot of resources and indexed databases for inequality, credit availability, remittances, etc.
----------- Non Govt Resources/Depositories ------------
Quandl seems to be an indexing/depository site that offers numerous databases, many of which are actually free/open. Many are also not.
As I said before, feel free to edit this and add to it. Financial/Banking databases are exceptionally decentralized and hard to come by, so I'm sure this post will definitely help someone in the future.