I could definitely do without the immature name calling, but if that's what gets you guys off, have fun.
I'll nibble at more potential bait...warning, long reply.
Go make a sandwich and grab a drink before reading.
If such is the case, then so be it. I'll try to word this reply in a manner such that I genuinely hope to not come off as a jerk.
For starters, you asked about cohabitation and got a fairly consensual response regarding this. Bear in mind, multiple topics of inquiry you've started would be very much "trolling bait" subjects -- particularly for a newly registered member. Again, not wanting be a jerk, but many of your subjected questions within this thread are thoroughly covered via the search function.
The caging question is subjective at best, as I'm one that prefers to house animals in larger environments than what 99% of the industry says. That said, many of my animals are in tubs, but I'm personally working on correcting such hypocrisy because I didn't purchase all these pet reptiles to house them in translucent plastic storage bins. You wanting to build something is admirable and a 20-40 gallon tank will be
temporarily adequate until you build described cage.
Revisiting mixed species/cohabitation...it is not a matter of if but a matter of when for what you've suggested as "roomies". As one that
attempted to co-hab animals when much younger with poor results, please avoid it. It can definitely be done, but full understanding of the species, possible interactions, niche requirements, behaviors, etc go into play doing such. And even then if achieved (and I use the term very loosely) it is a dynamic that must be closely monitored.
However, to reiterate, DO NOT ATTEMPT COHABITATION.
Pertaining to cedar/pine, both woods release tannins/oils that can be irritants with cedar being a known toxin to reptiles; that wonderfully pleasant scent from pine and cedar is said toxin. Aspen and/or fir bark chips are safer and typically less dusty preferred options. This is for bedding.
Habitat construction, it will be pricey, but hardwoods like oak would probably be better and are definitely non-toxic unlike cedar or pine. MDF/melamine can be used too, but will need to be thoroughly and properly sealed to avoid water damage. MDF and melamine covered MDF/particle board may also off-gas volatile compounds from glues that may cause damage over long term exposure.