Can someone explain to me the differences in each? I have a vintage Danger Zone and want it to be somewhat close in strength to that. what would you recommend?

The Guru Master is going to be much stronger than the Danger Zone, although with somewhat of a similar motion in the sense that they both read in the mids.

A Guru Mighty is a different animal. Cleaner down the lane with more backend. But that wasn't a particularly popular iteration of the Guru series if I remember correctly.

Neither of those two Gurus are going to be particularly close to the Danger Zone. A Jackpot Solid is more in that mold. Go for a Xeno if you want something a little bit stronger.

I'm just looking for something with around the same strength as the danger zone

With how balls are made for specific motions these days it's hard to recommend something based on strength alone. Some are earlier, some are later, and then there are those right in the middle. All can be the same strength but have vastly different looks on the lane.

Like I said before a Jackpot Solid is going to be the closest overall in the Radical lineup to a Danger Zone in the sense that both read the lanes in roughly the same area and can handle a medium to medium-heavy(ish) amount of oil.