Just a quick though looking at this. Why not have a simple piece of PL/SQL that reads the packages from the DBA_SOURCE Table and dumps it into a file on the file system. That way it can be made to be readable and held in a file. You may need to play with the formatting a little but I have done this for screens looking at stored packages in HTML and managed to get them to show very well and the retrieve is fast.
I know its not pretty, but could get over your initial issue.
I hope it helps a little.