Well there are many kits out there for your vehicle for bypass without losing a key. Whoever you are going to obviously just doesn't want to work on your car because it says Infiniti and through history they have been a biotch to work on. Find a good custom shop and they should be able to do it no problem.
I would recommend the SRT9000 from Code Alarm and the FLCAN bypass module made by Idata but I'm a bit bias as I work for both of those companies. The SRT9000 has a mile range and a really nice looking multi color LCD remote. The FLCAN allows for integration into the vehicle's anti theft system without losing a key, and also makes install easy for the shop because it gives them door trigger, locks, trunk, everything all in a few wires under the dash.
You can get them both from this website
http://www.autoalarmpro.com and do it yourself if you like. This is one of my customers and he will send you step by step instructions on how to install it and even a tech line for support.
Here is somebody local that I know of in your area......
http://www.customcarstereo.com/
Good Luck