When it comes to tool, just get a good brand name you recognize. Chicgo Phumatic, Snap-On (if you like to spend big busck), Crasftsman or Ingersoll Rand. For home use, stay with 3/8" or 1/2" impact wrench. Most home compressors will handle this. I have used both types of sprayers and like the downdraft easier to clean up after. The one tool that you did not mention is a sander. They will require a lot of air!. It is due to a constant drain of air unlike other tools that give the compressor time to recover.
As to the drain cock on the bottom of the tank. If you routinenly drain the water from your tank, you should not have much of a problem with water collecting. By having a leak in the air system you are making your compessor work longer and harder and reducing the life span of your compressor - motor, pump, tank, etc... Repair all leaks as soon as you can. It is just lazyness to let your air compessor leak.
No mater what kind of compressor you purchase or have they will squeeze the water out of the the air. Remember basic chemistry for junior high shcool. There are a lot of drains and fitlers you can install on your air lines that will help with the water problem. Also, oil all your tools up when you are using them to reduce the amount of corrosion that the water can cause. I use an inline descicant filter that I replace from time to time.