The BlackWidow is probably the Razer-product I have the least gripe against. But I mean, I see no reason to charge the price they do for it.
I personally have a G110 from Logitech. It suits
me, but these things are personal in my opinion. I'll likely get a hands-on experience with the Corsair K90 when they are to be released later this month, as I have high hopes for it.
For headsets - yea, you can run them alone, or, run them on the USB-versions for
their integrated sound (ie, usb sound card). A real proper sound card is always better though.
I use a PC360 from Sennheiser, which along with the A40 is likely the best (gaming)headset around. It simply is that good.
You don't need a sound card to drive them, but their potential increase even further if you do.
These are also, in difference to the Razer/Steelseries and alike headsets very good for music, too.
Also, for keyboards if you are willing to forego the backlight-effect, the 6g v2 and 7g from steelseries are pretty good.
And MicroSoft Sidewinder x4 is very very good for value, with backlight (not sure on the light though)