When I get to the point of tweaking with power settings on the mesh nodes and installing omnidirectional antennas, how would I figure out the optimal configurations. I want the ability for each node to have their own dedicated power source...of course. If I recall, the higher the gain on an antenna, the more power it will require. Ideally, you would want your mesh to cover as much space as possible and likely with the least nodes as possible. So what is an ideal gain for an antenna (for distance and power requirements) and what power would be needed? Granted, we're probably not talking about pushing 10 miles from one node to another, so I get that, Im kind of trying to figure out what all I will need, in hardware and what I should expect for distances (to figure coverage) between nodes.

Antenna gain doesn't directly relate to power consumption, it only relates in the fact with higher gain antennas the beam is more focused and it is possible the RF transmitter could use less RF energy (and by extension less DC energy) to go the same distance.

Antenna selection is a whole category of its own.  There have been discussions in the forum on this about Polarity, gain, etc that would be a good read as well as the WNDW book would likely also have some good documentation on this to get you started.