Best heated beds

I am looking for a SAFE and effective cat/dog heated bed that can be used all the time. I have four cats and would like the bed to be large. I will place it on my bed as that is where the guys sleep. Are there beds that can be on 24 hours all the time or with a timer? Are ther beds that last more than one year? I would really like input about the types of beds out there and your experiences. What about reg. (human) heated blankets? I also saw a cat/dog blanket for sale. These are not inexpensive items so I want to get the best for the money and something that will last more than a year. This is my first time on this site, actually on a cat fourm. I have been reading about the beds on amazon.com and not getting much there. Please help. Thanks, Molly

I have one I bought at Petco for about $30 and it has been left on 24/7. I had a human heated blanket before that, but with cats it had to be washed so often that it stopped getting warm. My heated bed is just a heating pad-type thing with a foam bed & washable cover.

I have 2 Sleepy Pods with 2 heating pads and they are really nice but way too small for dogs.

http://www.meowme.com/

There are a bunch of heated sleeping pads on http://www.drsfostersmith.com but I don't know much about them.

The bed is for cats not dogs, it's just that I have four and want them all to sleep on it together.
What is the brand of the one from Petco? thanks, molly

I don't know the brand - it wasn't in a box, and there isn't a tag I can see. It is much (if not exactly) like this one. Except I paid $32 for mine.