I am about to undertake building all new wooden enclosures for the boas and balls. I would like suggestions on heating the all wood w/ plexiglass sliding door enclosures. I am thinking I will go with RHP from ReptileBasics I am working with one of the guys there on exact sizes but we are aiming for the 80w for the balls that will be in 4'x2'x18" enclosures and 120w for the boas that will be in 6'x2'x18" enclosures however I am finding varying information on rather or not this will maintain the temp gradient needed most of the bad reviews are in pvc cages will the wooden enclosure hold the temp gradient better. Also for the RHP do you recommend proportional or on/off style thermostats I am considering it will be better to hook each thermostat individually to each cage rather than one thermostat to control all RHP. If the RHP will not be sufficient should I also use belly heat in the form of an intellimat or flexwatt heat tape. my average room temp varies according to the season but generally between 65-75. for day night cycle we are going to use standard under cabinet mounting florescent one on either side of the cage with a white light and a black night for night viewing. We are trying to keep everything internal as these cages will be stacked. Substrate will be reptibark as we have found it to be the easiest to clean as well as less messier than aspen. We are also debating swing open doors or sliding doors so far everything we have found would suggest that sliding doors are more reliable at keeping the snakes in as they do not warp over time like the swing open would near the middle from being pushed on from the inside over time.
Also when treating the wood prior to building the cage what water sealant is best or should we paint with latex paint to make it easier to clean and more water resistant. with the RHP would it be better to mount it centered in each cage or off to one side. Also if I set the RHP to 90 degrees and place the probe directly under it will that be a sufficient thermostat heat setting. I have a pretty decent sized budget for this expenditure and am hoping to set everything up with optimal management of heat humidity and overall clean look of things. I do not like the animal plastics or the boaphiles for several different reasons but main one is simply just my taste I prefer the look of wood we will have only 8 snakes and do not intend to get more than that 5 are already here and I will be buying 1 more boa and 2 more balls with in a couple of years and duplicating DIY cages is much easier than ensuring that a company is still carrying your exact cage. Each cage will also have its own sonic mister.

To recap from my large explanation and paragraph of questions

RHP?'s
1. 80w for the 4'x2'x18" and 120w for the 6'x2'x18" enclosures - Is this sufficient or do I need another heat source to maintain the gradient in a cooler room? - heating the room not an option
2. Mount RHP centered or to one side? - for best results overall
3. do you recommend proportional or on/off style thermostats? Why or Why not please?

Doors
1. Is sliding glass or swing open better for long term use with minimal replacement?

Thermostats
1. What temp would you set the RHP to on an on/off?
2. What temp would you set the RHP to on a proportional?

Treating or Painting wood?
1. What would you treat the wood first with as a sealant?
2. If no sealant would a latex paint be better for cleaning and uping the water resistance?

Lighting?
1. Would it be ok to use under cabinet mounting lights one with a white bulb one with a black bulb for day night cycle and night viewing? Why or Why not? Alternative suggestions?