The absolute highest end/best keyboard & mouse set up that I can think of is the Leopold FC660/C and the Zowie AM or Zowie FK

A set up like this, -- with (IMO) the best compact Topre keyboard and mouse -- however, is an acquired taste. It is completely no frills and pure craftsmanship, performance, and in my opinion the most aesthetically pleasing.

I highly recommend that you do not purchase the Logitech keyboard or the Rat9. I know several people who have gotten those products and absolutely despised them within a few months. Their build quality is shoddy, they are overpriced, are bloated with software/special drivers, and they are prone to malfunctioning or breaking.

It maxes at 2000 dpi, but I've heard that more is better?

This is a common misconception. DPI (you may have also heard the term CPI: Counts Per Inch) only refers to the ratio between the amount of distance that your mouse moves in real life versus the distance it moves on your screen. In other words, how fast your cursor moves. It does not refer to how accurate or responsive your mouse is. That is all dependent on the sensor that your mouse uses. There are claims of "flawless sensors" but the more research you do into the topic the more you realize that there really is no such thing. The best sensor on the market is the Avago ADNS 3090, so look for mice using that. You can find some differing opinions/additional reading here