Rack system help; For future reference.

I don't have racks yet, but when I do get them/or make them I want to make sure I get everything right. Especially if I make them.

Tubs;
What sizes for each "age group"/How often do you who use tubs/racks switch your snakes from tub to tub?
What type of tub do you reccomend? (Transparent, blacked-out, other?)

Materials & Heating;
What is the best material for the rack itself to be made out of?
Depending on the kind of rack (I'm pretty sure there is more then 1 kind/model right?) how would I heat the rack?
What type of thermostat would I need to get?

Cleaning;
Besides cleaning the individual tubs, would I need to clean the spaces where the tubs are placed?

Bedding;
Any bedding will do, right?
Besides pine and cedar products of course.

Water bowls;
Deli cups with reinforcement?

Any other info you can give ontop of this is greatly appreciated. :)

I currently use two different size tubs. 32qts for adults over 500g and 12qts for snakes under 500g.

I used a pre-finished particle board similar to melamine but with a wood veneer.

Flexwatt

Johnson, Ranco, Helix or Herpstat. Don't settle for anything less then one of those four.

I just wipe down the shelves with a damp rag. Not much else cleaning you need to do.

Paper towels, newspaper, cypress mulch, aspen.

I use ceramic dishes for water bowls. If you use deli cups you will need something to hold them in place and keep them from getting tipped.

I got self made racks ( 2 soon to be 3 ) I have about 3/8 to 1/2 plywood ( need to redo the shelves to the thicker wood to prevent bowind more.)
I set all my snake up in 41 quart tubs. all different weights no problems for me.
I built my rack so the lid was still on the tubs for extra secured tub no escape chances unless I leave the tub unlocked.

I use Johnson thermostats on both racks and set it up with a heavey ext cord ( like you use outside) and a power strip plug for the flexwatt ( each shlef got it own plus so I can turn off unused shelves.)

I have aspen shavings in my tubs( which are sterlite clear ones) with those dog water bowls I get the medium ( about 90 floz one I think it was I need ot check next time at walmarts) they don't tip these too much.
I also check andwipe the shelves down ever month this help remocve and dust that settle on the shelves and I can checl my flexwatt for any wearing from the tubs slidding on the tape.

other advice
if you build the rack assembly in the room it will stay is best. if using flexwatt tape I asl othink it easier to place ( foil tape ) or something else to hold in place when you set the shelf in cause it had to work in a 8-9" gap after words. I do set my tubs up so they not tight tight ( about a cd case worth of space between the tub and the next shelf ) mainly to make the tubs last longer and to have a little give for bowing.

I aldo use a 1x4 front piece onthe bottom to make sure the rack does not sit on the floor ( need to set mine up so air will move under there or the bottom shelf is colder than the rest .

Mechnut, structurally speaking, for your rack, I'd make a frame of 2x4s that will be stable on it's own and attach the plywood and shelves to that.