Additional loops & music sources?

(BG Noob) Any recommendations for additional Apple Loops from 3rd party vendors?

I have found a huge range of offerings for Apple Loops from 3rd party vendors. Hard to sift through the rubble to find the gold. Important that I can preview, esp when buying large collections. Is it unrealistic to search for individual loops based on current needs?

Is there no such thing as "free" downloads? Most seem to be a hook to purchase loops.

Also, I tend to use loops for the "rhythm section" and then create melody lines from the available library instruments, using either keyboard or guitar. Are there 3rd party options for the library instruments?

And lastly, I am typically creating music tracks for videos. Not much of a musician myself. Any suggested sources for longer "loops" (if that is what they would still be)?

Are there sites where I can hire a real musician to create custom music tracks?