It depends
I personally don't use samples that much, but I play many instruments. Good samples can come from anywhere, it's how you use them. What kind of samples are you looking for, drum loops, voices, or something to base your whole beat on?
When I do take samples I do like most Hip Hop producers and use Jazz samples, not acid jazz, the older stuff, and also classical music, there's alot to sample from classical. There are also some alternative music groups out of europe who's music has been sampled alot, especially by the beatminers.
What kind of Rap? Some of the more "Pop contemporary" rap producers use samples from those british rock groups that were popular in the 80s, THe police, Scriti politi. They don't take the whole sample, they usually replay some of the melodies or an intro from a song. There are so many ways you can get good samples, so many places. You just gotta listen to a lot of stuff that you normally don't listen to, ask a friend near you. You can also mess with the samples and come up with your own sound.
As far as hardware, how much you lookin to spend?
