Housing juvie\adult beardies together is possible, but not recommended, espeically for beginners. It can stress them out (even seeing other lizards in the same room) and in some cases, lead to fights, wounds, and death.

40 gal breeder tanks are fine as a min. If you can build your own or otherwise go bigger, that is great. They are not climbers, so go for floor space over higher sides (breeder tanks are great in this way).

MVB rocks. Basking spot heat and UVB all in one.