Sounds like you're on the right track to get more "oomph". IMO an efficient vented cabinet with efficient drivers is the key rather than expecting a rectifier change to boost your SPLs, as loudthud posts you're only dealing with a paltry (by modern standards) 60 watts.
Transistor watts are so cheap, and the focus is so aimed at small and light now days, that cab efficiency doesn't seem to be a real high priority for manufacturers.