I am looking for this same kind of solution right now. I want to be able to trigger specific samples or loops from my FC-12. (example: I will record the sequencer and the piano part for Baba O'riley, and want to trigger each part in the song by selecting a scene on my FC12, and sending a midi signal as part of that scene.)
I have been using Ableton for years to play backing tracks, but like the OP, I no longer want to deal with a Laptop. I just want a small dedicated hardware device to do the job. The liquid tracks might have been a good option, but it doesn't seem like that company is operating or stable enough to give money to at least.
I am looking at some dedicated sampling machines, but was wondering if anyone else has any other ideas or ways that they do this. RushFan, I', checking into your method... not much info available on that app though. I checked out the Akai MPX products, and that came close, but is not quite right due to the need for the SD card and how slow it loads. It doesn't seem strong enough to load and play longer samples in a live setting.
Man, there is a need for a device here. Could you imagine if the AXE had a built in sample player - like a more robust version of the looper where you could trigger individual loops or samples with a scene? You would have an all in one performance machine. That would be an amazing AXE IV idea, and I would drop my $$$ on it right now.