November 9, 2014:  Finally got around to drawing my home's layout and beginning to figure out what I want to use to heat and materials I am going to need.  The following picture is the 1st floor of Casa de Snood (CDS) that my family and I spend 80+% of our waking hours in living.  Note that while we have a propane-fueled, forced air heating/cooling system, the great room, kitchen, and dining rooms are a good 7 degrees F to 10 degrees F colder than the bedrooms and bathrooms in the winter (lopsided as all heck!  

  ).
Note: Scale of the drawing is 1 square on the graph paper is 1 foot of length/width.
In order to heat this space and the basement and garage, I first drew the layout of the areas and then used colored pencils to kind of figure out where I was going to run copper pipe and Pex for radiant floor heating (the 
red-dashed line area situated below the kitchen, dining room, and part of the great room).  Here is my basement/garage drawing and thoughts on paper:
Note: Scale of the drawing is 1 square on the graph paper is 1 foot of length/width.
Basic heating system layout I have in mind includes the following:
- 20-plate heat exchanger for the water heater
 - water-to-air heat exchanger for the forced air system (plenum size is 17" x 21" )
 - 1/2" PEXa radiant loops (for radiant floor heating in the entire Great Room, Ktichen, and Dining Room)
 - 60,000 to 100,000 BTU/hr unit heater in the garage hanging from the ceiling
 - a Watts 5-loop stainless steel manifold (or similar) for radiant loops
 - Grundfos pump(s) as needed
 
Aside from the radiant floor loops (total number of zones is undetermined at this point) being 1/2-inch PEXa, I intend on using copper and bronze ball valves for the main loop of the plumbing.  
Any suggestions system designers?  Need to start gathering materials. ;-)