URS Beta was mentioned in my reply.
As for better, it all depends on what you are trying to do.
If you actually want to USE the releases, yes, URS Beta would probably be better.
If you actually want to look at and LEARN from the releases, I mentioned UNoLimited first because, well, that is ALL it does is control how items are spawned. It would have less code, less possibility of confusion when learning from it.
The other two, including current URS Beta, actually control more than just spawning items.
As for compatibility, sorry, no idea. DarkRP has been a mess of code for years. Though (at least) a half-way decent developer took over some of its development in the past few years, I feel it's poor origination and development in the beginnings ruined it for anyone afterwards, current developer included.