I know this is a woodworking forum, but I'm going to go to extremes here and say that you may want to clarify your question a bit. What I mean is are you going to be working on cars (the "extreme" part of my post) or making fine furniture? Small projects, large projects, or what?
The reason I say that is there are a lot of options when putting together a good shop. Some will not live without certain tools, others say they are not important at all. It depends on what your skills and intentions are...
But you have one thing already in mind that will save you TONS of headaches... Lots of storage for lumber...
Now, with that said, I would think any woodworker would want certain things in his shop, at least 95% would...
1. A table saw
2. A good workbench, or two... or three... or more
3. A drill press
4. LOTS of storage for small tools, bits, blades, screws, glue, varnish, paint, etc.
5. Clamps out the.... uh... ying-yang
You say you have lots of hand tools and I'm assuming you are talking planes, drills, hammers, sanders, routers, etc. so I won't go into the smaller tools.
After the first five, which are not in PERFECT order, but close on my list, I would start considering:
1. Miter or radial arm saw.
2. Router table
4. Planer (if you plan on buying any rough lumber.)
5. Disk/belt sander
6. Band saw
Then there is the idea of a lathe. Are you wanting to start out doing turning? If so, that may go up the priority list...
Of course, this is one man's opinion and I'll be very surprised if you get two answers that are exactly the same... But I'm willing to bet my top 5 list is going to be close...
Good luck with your shop and know that I'm envious... I'm renting and can't build anything at my house like that. I have to settle for my half of the garage until we buy...