What racks and tub sizes does everyone use?

Ive been doing some research on the proper size tubs to house ball pythons and it seems that the order is 6t/16qt/32qt/41qt. For those of you who breed/have racks do you have a rack for every sized tub? Also general question, do you use the sized tubs I mention? Dishing out for a 6qt rack only for it to be used for 2 months seems like skipping the 6qt size altogether would be a more economically feasible move. Lastly I know there are a few good rack websites, which do you use, and why?

I use 32 quart for youngins, and 55 quart for adults. When they are really little I just give them hides in the tub that fit them. No need for tiny tubs, unless I start breeding, then I will get small tubs, simply to fit all the hatchlings in the rack.
I use one rack, with different size tubs in it currently. I will be getting a hatchling rack for breeding.

My babies that i have picked up start out in 13qt tubs and move up to 28qt tubs, my 1000+ are getting ready to go into CB70 tubs when that rack arrives. I use VE racks from RBI for their versatility of being able to use 3 different size tubs in 1 rack.

I mainly use 3 sizes unless there are special circumstences.

V18 from out of the egg to 600 grams

32 quarts for male and female up to 2000 grams

V70 for females above 2000 grams

I use 3qt (same floor as a 6qt but half the height), 6qt, 28qt and final 41qt for my breeder females.