My Friend converted his shoptask, don't recall the exact model, but it came with the pulleys to drive the stock screws with N34 steppers.
We opted for N23 steppers for more speed.
It uses a Keling 50V 10A Toroidal powersupply, a modified open source breakout board, PCB from PMinMO and runs on EMC2. Keling steppers & Gecko G251's make things move.
EMC2 also switches on machine power(1) and spindle(2) and a "soft" E-stop will drop all that, while a hard e-stop drops all that and does a DC power dump.
Several others have also done shoptask's, problem is almost all did it differently. I don't know of anyone who bought a turnkey and just chose to switch the software.