Re: dry stools / best "type" of water (distilled, etc.) to hydrate the body?
Spring or well water is your best bet. R/O and distilled waters are very solvent and can rob your body of nutrients.
Alkaline Waters are just flat out dangerous. The so-called clustered waters are just basically heavily purified waters. They absorb faster for this reason, but also leave the body just as quick for the same reason.
Avoid stimulant laxatives, which just weaken peristalsis even more over time. These include senna, cascara sagrada, rhubarb root, and aloe leaf concentrates.
You could try adding some slippery elm or marshmallow root to your supplements. These do a great job of holding moisture and form a slippery mucilage. In other words make a great stool softener. Seaweeds are also good for moisture retention.
Make sure you are getting some good fats in your diet.
And I highly recommend checking your basal body temperature for at least a week to rule out hypothyroidism. This is very common, can cause chronic constipation, and is almost always missed by conventional lab tests. Basal body temperature is a lot more accurate in determining hypothyroidism, but not its cause. Instructions can be easily found on the web.