Yup, I've looked at a few different packages, unreal-archive being one of them, but as my php skills are basic at best I'm still limited in my progress. Got uz, uz2 and uz3 file verification/validation done so far but that’s about it.
I'll continue to poke about with the above dependency tool and see if I can take advantage of its functionality. It would be nice if someone upped your package to github and the work expanded, unfortunately I've little to no experience with github myself
I’ll try and play about with it in the coming weeks and if I can I’ll try and get it up there, if not, maybe Shrimp might be in a position add it to his account even, he has a few there already! Would be nice to get it included in unreal-archive too 
like the wiki’s section.Anyway, thanks for your php class, it’s a great resource!
arden