Thanks for your advice!!!! You guys have recommended a crate???

Which crate is better, A or B? How long would I use the crate? Would I use it as her bed? If we leave her do I leave her in there? Do I stop using it after a certain age and get her a doggy bed? THANKS!!!!
A
http://www.petsmart.com/media/ps/ima...8067_46ca7.jpg
B
http://www.petsmart.com/media/ps/ima...2447_13e6b.jpg