Are you so new to cycling that you don't know your proper saddle height, or the stack and reach of your previous bike? That's what stack and reach are for - to allow accurate comparisons of different frames. Reach can only be compared at the same stack height, so a larger frame with a taller stack is being compared, the reach should be reduced by 3mm for each 10mm of additional stack.

If the inseam posted is cycling inseam from floor to firm crotch contact in bare feet, the a typical saddle height might be around 79cm. My inseam is 83cm and my saddle height is 73cm. I use a stack that allows an 8-10cm saddle to bar drop, with a -6 or -17 stem. That requires a stack of about 525mm, plus the standard 15mm headset top cover and no spacers. My latest frames have about 15mm less stack height, so I use a 30mm tall headset to cover and no spacers.

If you really need to cut much off your post, you bought the wrong size frame.