the AKAI MPC2000XL is a popular choice but a little finiky to use. around 500-650 GBP depending on which add-on boards its has - for live use you'll really need the 8output board.

A laptop and ableton live is what i use, it might suit you.

A yamaha RM!x and an AKAI s2000 also could serve your purpose or you might try the yamaha su700.