I used this company:
Custom Laser Cutting Service and they did an awesome job for my side window. Though I just got a basic rectangular piece with a 120mm fan port.
You basically draw whatever you want using AutoCAD (or similar) or a vector-graphic program and send it to them with the material you want them to cut it on. Prices are fairly reasonable and shipping was good too.
If you use a thick enough material, they should be able to etch your logo into it.