I know you're sorted now, but re. the AKAI's..
If you want to sample, it will have to be the MPX16. The MPX8 only plays back samples stored via SD card
Also, the MPX8 is a right bar steward....finicky about formats ( 16 bit WAV only and stereo WAVS halve the memory ), getting samples to load can be a pain, lots of load time if samples are big MB's
Maybe the MPX16 is a similar nightmare, only with the ability to sample being the difference
Best avoided