Sounds like a great camera combo, both of which I was looking at myself.
Here is what Ken Rockwell said about the D300
here:
The Nikon D300 is the world's best amateur camera.
The Nikon D300 is far more revolutionary than its specifications suggest. It completely obsoletes everything that came before it, and especially sends the D200 and D2Xs to the dumpsters of digital history.
I've never said this before of any other camera, but the D300 actually makes it easier to create significantly better images than with earlier cameras.
The D300 has better color, better highlights, better shadows, it's sharper because it fixes lens flaws, and its superior AF system and viewfinder free us to compose more freely than any previous camera. The D300 shares these innovations with its nearly identical $5,000 big brother, the D3. Compare their menus or read their users manuals and you'll see that they are the same on the inside! Owning both, I can confirm that they both operate in the same way and give the same look to their images. At ISO 200 with an exceptional lens, there isn't any visible difference I can see.
The D300's numerous internal tweaks and far more processing power have made huge strides forward in real image quality. These improvements are so significant than even a blind artist can see them. These may not be as immediately obvious to people less than fluent in creating images on a daily basis, since these innovations deal with subtle but crucial issues of color and value. Color and value are the critical foundations of every image, as every artist knows.
And... he loves that exact lens too,
here:
It's a miracle! I bought mine in November 2005 and love it. It's replaced an entire bag of lenses. All I bring anywhere is my 18-200mm, and maybe my 12-24mm for 99% of everything I shoot.
It's small, fun, flexible, sharp and fast. VR, instant auto/manual focus override and macro and zooming all work perfectly. This lens is too much fun! It has an almost all-encompassing zoom range and the images on my D200 are wonderful. Bravo! I have an entire page on Why VR is Important.