Hey Alex,
I'd suggest trying the install out yourself. When I bought my previous G35, I didn't know how to do anything on cars. It was a learning experience and I now enjoy working on my car. I saved A LOT of money by doing almost everything myself.
Yeah, I may take longer to complete installs compared to what a dealer, but the personal satisfaction and the money saving factor are worth it! Saving money on installs leaves more money for mods