There's just a tremendous amount of sample products out there - maybe it will help to categorize how these products are packaged.
Loops and Waves Some packages are loops and or one hits. These are usually wave files. These are quite easy if you are using audio loops for your drum track. It is possible to take these and load them into synths that allow you to build your own instruments, but it's quite a bit of work.
Instrument Libraries
These are packaged for direct usage by a synthesizer. Libraries are specific to particular samplers, such as Kontakt, Dimension, etc. It's important to know what type (or types) of library files your sampler uses. Some samplers can handle more than one type of file.
Synth/Libary/Embedded System
This is a system that includes its own sampler as well as it own samples. These packages generally use multi-layered samples that can change timbre somewhat in response to velocity. ToonTrack makes drum packages such as EZ Drummer this way. However, instrument libraries (as above) can also be crafted using multiple-layers for samplers that that have that capability - i.e. Kontakt.
There just a whole lot of google-surfing that needs to be done to find what you need...