How much growing do they have left?

Question
A stray domestic shorthair calico adopted me a while ago and since she didn't seem to be going to any home, after about a week I took her in to get her spayed to prevent feral kittens.  To my dismay, it turned out that she was already pregnant.  Not too long after that she gave birth to five kittens in my back yard.  Needless to say, I gave up and adopted her at that point.  Three spays, three nuters, a whole bunch of worming and shots, and three adoptions later, I still have three of her kittens.  It turns out that I'm a cat person.  

Mommy was never more than a seven or eight lb cat (and still isn't - I get regular updates on her from her new person) and the daughter we kept (my so/s favorite) is now only about six lbs, but her two sons (my favorites) are about 16 lbs each and are only now a year and a few months old.  (I should note that they are not overweight.)  Since most of what I've read suggests that cats aren't fully physically mature until they are three years old or more, how much more growing should I expect?  The boys are already much too large for most litter boxes and every cat bed that I've found.  I also worry about getting them cat furniture since most of it doesn't seem to have a base designed to accomidate larger cats.  Any suggestions of where to look to find cat items better suited to my boys would be greatly appreciated.  Thanks so much for your time.

Schrodinger, Macavity, and Zot's mom  

Answer
Jessica,

The most expensive place to buy cat stuff is at a pet shop.  On the other hand, a number of pet supermarkets do have more variety and somewhat better prices.  But, I have found, the best place to buy cat paraphernalia is at a cat show.  The down side is that you do not know ahead of time what vendors will be there, so it is hard to know what you may or may not find at the show.  Often cat tree vendors have all sizes and shapes of exercise posts, from kittten size to large cat (25 pounders) size.

To find out about cat shows in your area, go to

  http://www.cfa.org

and navigate to the show schsdule.  The shows are by date and by zip code within date.

You may also try some of the on-line places like:

K-V Vet supply, Fosters and Smith, or Revival.  You can do a google search and look at their on-line catalogues.

We have a 25 pound male Maine Coon and have not had a problem finding large enough covered litter pans for him.

As to the answer to your other question.  Depending on the breed cats may be fully mature by 18 months or not until 5 years of age.  Proportionally, males are usually larger than females.  Witrhout knowibng the sire of your kittens, it is difficult to estimate how large the males may still get.

I hope this helps.

Best regards... Norm.