Thanks for the replies. I think I'll go with the 45cm tall. I don't know how many gallons is the 90 x 45 x 45 but is that enough room for 5 or am I better sticking with 3?

2.0 Border Collies - Jinky and Chance
3.0 Cats - Monty, Dodger and Crunchie
1.1 Royal Pythons Orlina and Sedrick
0.1 BCI Boa - Aasia
1.0 Western Hognose - Hagrid
0.1 Bearded Dragon - iiara