About drying what you've milled. First, it's best to accept that you're likely to loose about 20% due to warping, splitting, etc., no matter what you do, or at least you won't get usable full length boards from that portion. Hickory is actually a little less of a problem drying than red oak, and I have very little problem with that. You'll have even less problem the more of it you quarter saw, but hickory looks better to me plain sawn.
I debated the whole solar kiln idea as well, and some good comments have been posted here. In the end, I decided to let mother nature do a lot of the work by just stickering the fresh cut lumber under some shade trees, covering it with corrugated roofing, and letting it dry for a season or two. I've found that one summer is enough to get the moisture content down to about 16% here in western NY. I then bring the wood into my cellar where I built a dehumidification kiln at a cost of about $200 that dries it down to the 8% I'm looking for for my furniture. I can dry 275 BF per load at a cost of less than $20 - cheap enough - in about 10 -14 days. I got the basic plans for the kiln from an excellent article in Fine Woodworking. The design could easily be reproduced for much larger quantities, and located in a garage, out-building, or even it's own stand-alone building. Drying wood is not hard, nor does it have to be expensive, but you have to have a plan before you cut the first board.
If you want to make flooring, trim, etc. you will need a planer and/or molding machine, no way around it, unless you like the feel of rough sawn lumber under your feet. Wear shoes if you do. Nailing down tongue and grooved hickory is no more difficult than any other hardwood using a pneumatic flooring nailer.
You are embarking on one monumental project. Good luck.