Thank you for the suggestions, I'll look into them to see if they do the job well.
(Still might not be a sufficient solution, since another add-on, Path Finder, apparently does a great job fixing these and other Finder deficiencies, yet introduces other issues due to limitations OSX imposes...
Thanks for your reply, and please pardon this very long clarification, but I wanted to be, well, clearer.
I know about that, but that method doesn't help in many situations (including the one I described, as I didn't have any clue what the sizes might be ahead of time... I could only know...
Specific example of a very common general scenario: I'm searching for an instruction manual on my computer. I have a lot of product brochures and one manual from the same company, all with similar names. No idea which is the manual, but I do know that when I run a Spotlight search, the manual...