Hi Adrian
That second shot would look great in Greyscale, you have brought out a lot more detail.
I may have mislead you in my first post, leave the green channel in the shot, try and reduce the reds, they seem to have overpowered the first shot, you will find the end result more natural.
With the unmodded 350D, you will find that it is sensitive to O111, that is what the green in your shots are. After a bit more practice and getting used to the camera, try shooting in RAW's and converting.
Google up, say, "Astrophotography with a DSLR" or similar and you will get a lot of information on using a DSLR, also try something like "Astrophotography and Photoshop" and you will also get a lot of hits and there are a number of sites that have short video's on using PS.
Anyway, your off to a great start.
Cheers
JohnG