Sturdy and Fast all Steel CNC , my first build

[JAZZCNC]

However i wonder what step/micro-stepping should i use with the 1605/z/ and the 1610/x,y/ ballscrews? having in mind the way i build the machine.

Well depends a lot on your PC and how good the parallel port is and what speeds your looking to achieve. PP and PC speed to some degree will determine the Kernal speed in Mach3 and how many pulses you can put out which in turn will determine the speed you'll get from the machine. Higher micro steps require more pulses to achieve same speed has lower MS but they give smoother running motors and to a lesser extent some resolution.
Personally I don't go higher than 10x or 2000ms and this is my preferred choice if PC can handle it. Higher MS also helps with resonance but these drives are great with handling resonance so it won't be a problem and if it is you can change tune it out using the software.

So i asume rising is Pul High and falling edge is Pul Low. I wonder which one will work with my C23 board from CNC4PC

I would agree but check with Arturo and I'm think it may even be possible to change a jumper on the board has well to suit but either way your covered because the drives allow it.
If you can't find out then you'll have to make some witness marks run some G-code and then check if it's lost position. If the pulse is on the wrong side it will drop a step on every direction change so won't take long to find.