[ger21]

The 2.5A/phase is the most the motor can draw. The power supply can be as many amps as you want, but depending on your motors, at least around 5A minimum. Email Jeff with your motor info, and he can tell you more accurately. Some 24V supplies can be adjustable up to usually 27V, but I haven't seen many. 30V are hard to find if you're on a budget, so most people go with 24V.

Resistors are for Unipolar drivers to regulate the current, none are needed with the Xylotex.

Did you get the 3 seperate boards? On the 3 axis board, Jeff supplies a power cable to plug right in to a PC hard drive power connector with the board. With 3 seperate boards, you'll probably have to wire them up yourself, but yes, you can use a PC supply for the 5V.

Gerry