Rismonite wrote:If you deep strike at least 9 inches away from any enemy units, do you need an eight or nine inch charge to get within 1 inch?
The wording for most (all?) the 'Deep Strike' abilities is "more than 9 inches", not "at least 9 inches".
There's an important difference between the two - the latter allows you to deploy at 9" while the former does not.
Because you aren't deployed at 9" from the opponent - but rather more than 9" - you need a 9" charge to get within 1" of the opponent.
Certain wargear options (like the T'au Homing Beacon) change how some of the 'Deep Strike' for their units works that can allow you to override their rule and be setup within 9", but they usually have a downside (like in the case of the Homing Beacon - it's destroyed when the enemy gets too close, and it restricts units that want to use it to deploy a short distance from the beacon itself).