Hi Pam, Welcome! Wow, 18 years old is pretty darn good for a Cockatiel, you must have been doing something right! Sorry to hear of Chewie's passing, but from the sounds of it he had a long and wonderful life with you and your family.
I think you'd probably really enjoy a quaker, they're a little bolder than a cockatiel and in my opinion a little stouter stock.
You might consider purchasing the book A guid to Quaker parrots, by Mattie Sue Athon....its like a Quaker bible...

Lots of information in that book and its relatively inexpensive, I find I refer to it quite often.
Anyway, its nice to see more and more people getting interested in these great little birds...they truly are a Big Bird in a little bird body!