To be certain you'll have touch up paint you will want to buy a gallon or so extra and be sure to have the salesperson write down the exact ingredients of the paint you choose. Luckily, there are machines available which can analyze a chip of paint but, there's that old saying about an ounce of prevention...it could save you from buying gallons later.
If you have the time: Turn off water, gas and electricity before leaving. Post a note telling when you left and where you are going. Don’t forget about your pets and be sure to lock your home.