Hmm... I think Budgies are pretty much the same as tiels when it comes to care.
Just get him good quality food and a cuttlebone. And change his food and water everyday. (You know that already, since you own tiels^^.)
I hear the *minimum* cage size for one budgie is 20"X12"X18"... of course Norri has a much bigger cage since he isn't tame.
Toys are nice to try. Some don't play with toys, though. Norri has 2-3 toys in his cage, though he doesn't play with them. He loves his swinging perch, though!

See? Basically the same as a tiel.