The Circuit Tracks probably wouldn’t work. The Circuit Rhythm might. I own one. It’s pretty great for what I do. I think it checks all of your boxes. However, if you need long samples or stereo samples, then it probably won’t work.
And if I were you I would probably try to see if the Blackbox can work before trying something else. I’ve never used one myself but it seems like a great sampler.
Probably one of the bigger things mentioned above, but at the extreme small end there’s the PocketOperator-33, sort of a miniature SP404 (which I hear are hard to find at the moment)…
1. Play a bunch of samples live, like movies’samples, and I’d like to have quick access to, at least, 64 samples (for example to play phrases word by word).
16 pads x 8 banks
This is the main function I’d like. I don’t need pad sensitivity (but hey, why not ?).
I’d also like to have easy access to usual paramaters : lenght, speed,…
(repeat & bit crusher if possible) 2. (optionnal) effects
4 effects per pad
3. (optionnal) live looping
Why yes it does this.
4. (optionnal) small form factor
MPC One: small form factor
MPC Live 1/2: portability