Vinyl's worth a download, (great for getting your loops nice and gritty) but it won't do what you asked. You're probably gonna want REX or Apple loops for this, if you go that route. You could also wrangle and mangle your own beats/noises in most samplers, time-stretch the sample and have it play forward/reverse and fiddle with it, 'til it's in tempo. There are at least a couple of VST plugins that can do something similar.
those loops sound useful, and for the purpose of giving the feeling of old school hip hop where you'd find those elements, they're better than trying to create the effect from scratch using forward/reverse effects on a sample. it might sound interesting but it just wont sound like the dj scratching you're looking for, unless you know how to make those sounds with a record and crossfader. but then if you did, you'd just use a program like serato and just do it.
if i could make a suggestion, if you do decide to use these loops. you can truncate them but for the most part, use them as they are, if you mess with it too much like chop them up and change the sequence, its going to sound very unnatural to someone who's familiar with what dj scratches actually sound like.
this is coming from someone who did the scratching stuff through the 90's competitively. when i hear cues using dj scratch loops wrong, it's very unsettling.