Although you should ask the question in the specific thread, I will reply anyway. If you have measured your inseam correctly, you have long legs. For long-legged guys having shorter bike with higher stack will result in a faster and more comfortable position.
How long (reach) should you go depends on the length of your arms and torso - if arms are long, you can accommodate better with longer stem, if not you are risking to screw you balance over BB and you should look for a longer frame to get nice pelvic tilt. How high (stack) depends heavily on your hip mobility and pelvis anatomy.
All that being said, Arow geometry is not for long-legged guys, you may try to get into perfomance-oriented position, but it wont be efficient and you will be twisted and in pain. If you don't care and still want the frame, get 510. You have to keep a lot of spacers beneath the stem or ride almost exclusively in relaxed-on-hoods position.