If you are looking for a fancy keyboard, there are thousands of options around. Logitech, Microsoft, Scorpion and all the brands available can give you options that the other brand doesnt have.  But in my opinion, what you want is a keyboard that LASTS and that you can keep for the next 4-5 CPU's you buy. Why spend money on technology that does not change? There is only one choice for that and Sadly that is Microsoft.

Here are my guidelines:

a)Stay away from generic, unless you want to buy 4-5 keyboards and mouse for your computer.

b)Logitech is a good choice if you buy the upper tier products.

c) Thermaltake keyboards and mice look amazing and have a lot of nice features. Unfortunately they dont have the same quality as the thermal products, and you will end up with some nice-looking garbage.

d) Microsoft products are made to last. From their cheap  versions to the more expensive anatomic-looking ones, they have been by far the best for more than 10 years now. You can get them as low as 14 dollars on ebay or some low price websites. I am against Microsoft and their policies, but alas... they do make good keyboards and mice.

Finally, be sure that you get a keyboard that you need. A good keyboard will probably do all the functions of keyboard and mouse at the same time. You wont have to use the mouse at all if it is a good keyboard. You will require to learn several shortcuts but there are some keyboards that have memory functions available.

Anatomic keyboards really help you if you have carpal tunnel syndrome or some of its symptoms, but its not the solution to your problems. That said, go visit a physical therapy doctor to fix it. He will send you to make wrist exercises. Dont fool yourself getting the anatomic shape keyboards with the hope to fix that.

For mice (mouse):
Be sure that you get optical. If your desk does not have the surface requirements for an optical mouse to work, be sure to get a thin mouse pad. Some companies give those away for free. 

Although Microsoft is still the best to manufacture Mouse (mice) in this case there are a lot of nice options. Even some generic are ok. The secret for an everlasting optical mouse is to keep it from falling to the ground. When they do fall, they laser inside gets miss-aligned and bye bye mouse!

Be safe