I'm not a Gar expert but I know my fair amount about them.
1. You'll have to check the state laws about that each state has its own individual laws about fish, but most of the time you can't transport a still living species of wild caught fish.
2. I do know that the needle nose gar has been CB but and yes there are others that are too like gators are.
3. Theres no actual white colored Gar by nature,(excluding the white colored under belly of them) unless it was a naturally occurring genetic deformity which is rare, I know of no specie that is commonly and naturally white.
4. Unless your lucky to possibly find an albino, or there is such a thing known as a platinum alligator gar, but those are CB in Thailand. Basically its just a normal gator gar but no pygmy just white.
Like I said I'm no expert so if anything in this post seems incorrect please correct me.