Help me build an incubator.

I am almost complete with a medium size chicken tractor. My next project is an incubator. I am looking for advice on where to salvage parts, how big to make it, design etc. I am very handy and have lots of tools and left over building supplies. Below are some parts I planned on using. I have spent a lot of time researching how to build them. My struggle is this is the first time building or owning an incubator and I want to build the best one I can with parts I already have or can get for free. I pride myself on repurposing and it is one of the main reasons I decided to raise chickens a couple years ago. I keep track of every cent spent and sell enough eggs to pay the feed bill. If I need to purchase anything for this incubator it will have to come from egg sales and I just spent it all on more chickens.

HAVE
Water heater thermostat
I have several light fixtures
A complete air hockey table with 110 volt fan has cord switch
Foam cooler measures 15"X11"X11" inside must be to small for that fan?
2" Dow board the pink foam
Lumber
Tempered glass panes
Plastic bread flats

WANTS
Where can I salvage a motor for an egg turner?
Something to measure temp and humidity (does it have to be digital or can I swipe my wife's 3 gauge weather station off the wall)

After starting to develop a parts list I think I need to know more about the design before I get to far. I was thinking about making a triple wall box. Interior wall would be the fine peg board of the air hockey table, then a space to mount the fan and lights, then 2" Dow board and finally the exterior wall.

Questions to much not enough air flow? How big can I make it for the fan I have?.....going to pull fan today and see if it lists what are they....CFM's?

This build is over. Look what I just got for $50.

I found a couple of links through Pinterest and the one below looks useful as a starter:

http://www.cyberquail.com/incubators.html