As for temperature requirements, It depends on what species you can get. Its not very easy getting one in the US due to their poor tolerance for shipping. But occasionaly, some LFS night get one.
The most commonly imported species is sepia bandensis, although these do not grow big and can be housed in smaller aquariums ( mine is doing well in a 25g), they are frequently sold as 3-4 inch adults with not too long more to live.
Cuttlefish can jet around at an incredibly high speed, and can get infections if they hit something hard while doing so. This is called butt burn, so its best for the tank to be longer rather than taller. Cuttlefish are more prone to inking than octopuses so a Protein skimmer will be needed, activated carbon will also help remove some of the ink. They will usually only ink the first few nights but after that, it gets used to its new surroundings and only inks when frightened or cornered by an object such as a hand.
I'm not sure what other questions might be bugging you so just ask and I'll reply as fast as I can.