Any Japanese keyboard you could probably get to work on your operating system, at least partially - they look something like this:
You would probably have to order one from the internet somewhere. I'm not sure how compatible all the features would be if you're not running a Japanese version of Windows, though.
The question is whether it would be of any use to you. Do you use かな入力 for typing? (e.g., do you type by pressing one key per kana), or ローマ字入力? (e.g. typing "ka" for か).
I have heard that kana input is faster overall but you have to learn where everything is laid out so it takes more time to get used to. Romaji input is what most people use (including native speakers, particularly the younger generation), and you don't need a special keyboard, just an IME of some sort.
It's not the matter of the keyboard but the matter of the input method. You're using "kana input method" now. Try "Ctrl ツ+ Shift ツ+ Caps Lock" and change it to "romaji input method".;-)