Standard Health Dept requirement, Paul.
Let's see, how about an addition. You never will have all the space you need. Just seems to work out that way. By processing do you mean extracting? Or is "processing and packing" just straining stored honey and then bottling it. Keep "processing and packing" separate from extracting as much as possible.
-Water, hot and cold
-Good lighting
-Good ventilation
-More electric than you think you need (I have two Maxant Bottling tanks on the same wall and can't run them on outlets on that wall. Breaker isn't heavy enough.)
-Floor drains are nice.
-Washable walls are nice
-Tables and shelves for labeling jars and for storing labels and stuff.
-Shelves to store boxes of caps
-Space to store empty jar inventory, maybe on pallets on the floor
-Space to put full jar inventory for bottling ahead in anticipation of sales
See? Already filled your garage.

You'll figure out what you need and what you can do w/out. [just between you and me, a two basin kitchen sink is ideal for washing 5 gallon buckets. i wouldn't worry about a three bowl sink.]