New Machine: Configuration

[sirevert]

My CNC-project is taking forever to complete, but now I think I'm finally there:

2 ball-screws with 5mm pitch
2 drivers 50VDC, 4.2A, 300KHz, 400-25600 MicroSteps/rev.
http://www.stepper-drives.co.uk/down..._datasheet.pdf
2 48V 7A power supplies (currently only 1 connected)
http://www.motioncontrolproducts.co....ower_supplies/
4 3Nm steppers (2X, Y, Z)
http://www.stepper-drives.co.uk/down...H88-3008DF.pdf
1 water cooled 2.2KW spindle 8-24k rpm

I'm controlling the drivers with USBCNC
http://www.edingcnc.com/upload/files..._man_v3.49.pdf

Now I'm planning to work mostly with wood but I have no clue what would be the correct configuration.

Right now I'm running at:
125000 max step frequency (what effect has lowering this?)
25600 MicroSteps/rev.
5120 Step/AppUnit

Which results in my G-code drawings being 1:1 with the output. But it's pretty slow.

Is it slow? How "fast" should the machine work with wood? Can someone point me in the right direction concerning these settings. Or direct me to the correct information so I can figure it out myself [or a combination of both ]

Thanks for your time!