When it comes to sound old hardware sampler are overhyped IMO. Only people who make music and know the machines will care. People who are "just" listening really don't care about the machines. What many people often forget is the way these old machines are limited (channels, polyphony, sampletime, no waveform display etc) and the fun to turn knobs and faders and of course the psychological effect sitting in front of a machine that was used by xyz.
The 950 plugin doesn't sound like the 950 and even if it would it doesn't kick you in the direction to make music that sound like your musical heros from the 90s. That was the bad news. Now the good news is: You can still make that kind of music.
1. Download OpenMPT
2. set the Resampling to 'no interpolation'
3. in sample edit use normalize and then amplify just a bit more to your taste (120%-180%)
3. select the whole sample and resample to a lower samplerate (try 13020)
4. Alternatively you can render your sample(s) a few semitones up then use step2 and 3 and play it back in its original pitch.
5. If it sounds too harsh use a nice free filter plugin (SonEQFREE, Filterbank v3, TDR Nova) to cut some of the high frequencies.
6. IMPORTANT: Limit samplelength. Don't use more than 10 seconds sampletime (not for one sample but for all together!). Don't use more than 8 channels. Not more than 32 samples
OpenMPT is perfect for the genres you mentioned. Theres really no need to spend money on a plugin that won't really work.
BTW I love hardware (got the s900, the s950, TX16W, FZ1, Roland S10 , MPC2000 and worked with the Roland W30,Emu E64, s3000). But I also love OpenMPT because the way it sound and the fun factor while making music is camparable to hardware. Not like the usual DAW.