How exciting! Don't feel bad about getting a new ring. When we went WB shopping a few weeks ago, I was having a hard time finding a matching band that I liked, so FI suggested I just get a new ring, but I love my setting, so I ended up leaving there with a new center stone that was double the size of my original, and a simple band to match.
Like you said, this is something you will have forever, so make sure you get exactly what you want.