The Deathstalker is a joke. It uses chiclet-style keys and offers little to no usable feedback. I have a Blackwidow Ultimate and use it as my primary board. That said, there are better available. I continue to use mine simply because it's backlit and the Ryos Pro isn't out yet. I have had issues with multiple switch failures, which started occurring within a month of the warranty ending. If you have the savvy, it's easy enough to fix.
If money isn't a concern, I would strongly recommend choosing a mechanical board. Nothing with membrane switches is going to be better, though there are some good membrane boards out there. I have Cherry MX boards from Rosewill and Tt as well. Both are better builds than the Blackwidow, with the Tt being the best of all three. If you know what switches you would want, that would help narrow down a good board for you. If you need more info, just ask. Mechanical planks are sort of my thing. Whatever you want in a board, someone probably makes it.
As for the mouse, I actually prefer the Deathadder for a FPS, unless you are playing something with complex keybindings that would benefit from more macros. Historically, Razer hasn't had the best luck with their rechargeable batteries, which has kept me using my Deathadder even as I add more MMOs to my library. The Ouroboros and Naga are both good mice, and I like that the Ouroboros uses a rechargeable AA which you can replace on your own. I do not think it is worth $150 unless you have some incredible need to precisely configure your mouse, though you should be free to do that if you want. I have a friend who actually had his hand crushed and pretty much has to use such a mouse. He uses a Mad Catz R.A.T. I think it's a 9, but I don't know for sure.
For the headset, you are probably going to want digital surround. As great as the Tiamat 7.1 sounds on paper, it sort of falls short in execution. I absolutely love the idea, but it inherently limits the depth of bass and gives less than stellar sound quality. Give it another gen or two and it will probably be there. I personally use a pair of Megalodon 7.1s. This is a USB headset and works by taking over audio processing from computer. The biggest problem with these and other similar headsets is that they can be buggy. You have to mind USB suspend settings, keep track of the mixer on both the computer and the headset itself, and hope to hell it doesn't screw itself up when your back is turned. Also, forget about using it Linux. I spent four or five hours spitting code into the terminal trying to fix it, to no avail. Also, the headset itself is very delicately built, something shared across the Razer line. They are well made, just delicate. If you are moderately careful, you should be fine. As above, I like Astros, though they are a bit spendy.
In short, I have some $350 in Razer peripherals and they are okay. Would I do it again? Probably not, but they all work together well. Synapse has improved greatly and is actually useful. Their customer service, while not great, is nowhere near as bad as some say.
I would suggest looking at Coolermaster and Tt for the board. A Razer mouse is fine, but maybe look at the Roccat Kone X or a better Logitech. Astro would be a good headset, though I do like my Razer and even the Turtle Beach (I know, crucify me) I had before it.