Are there third-party keyboards that have the Apple layout?

Apple keyboards are different than PC keyboard because the Command ⌘ and Option/Alt ⌥ keys are switched. This causes a workflow disruption for me, because I use keyboard shortcuts for everything. I can't really use a Windows keyboard for my Mac, because of this problem.

Here's the Apple keyboard:

And the Windows keyboard:

Are there any third-part keyboards that have the Apple layout?

You can actually change the layout of your Windows keyboard. Go to System Preferences, Keyboard, and in the Keyboard tab, you will see a button "Modifier Keys..." Click on it and you can change the external keyboard layout.

For me, I mapped ALT key on external keyboard to Command and the Window key to alt/option, so my external PC keyboard now has the exact same layout as OS X keyboard.

Yes, there are several companies producing keyboards with Maclayout, e.g. Logitech: http://reviews.logitech.com/7061/4741/logitech-dinovo-keyboard-mac-edition-reviews/reviews.htm, and also Keysonic: http://www.computerbild.de/artikel/cb-News-PC-Hardware-Keysonic-ACK-540-MAC-RF-Spezialtastatur-fuer-Apple-Rechner-3364609.html

There are many. Here are a few.

Matias Keyboards

MacAlly Keyboards

Happy Hacking Keyboard Lite 2

Kensington, Adesso and Logitech also offer keyboards for Mac, or keyboards you can adapt to use on a Mac. You can use any Windows-style keyboard with a Mac. You just remap the command and option keys.

I've never liked Apple's keyboards or mice, and I've been using third-party replacements on my Macs since the early 1990s.

Here's the list of dozens of third-party keyboards for sale at MacMall.

If you like old school "clicky" keyboards:

daskeyboard Model S Professional For Mac

Unicomp Spacesaver M

Razer has a Mac-layout of their BlackWidow mechanical keyboard.

http://store.razerzone.com/store/razerusa/en_US/pd/productID.211324200

Beyond that, it's fairly easy to remap the keys (which is what I've done) so they obey your Apple-created muscle memory.