Forget the supercharger and get a Turbo!
With the turbo kit you have the ability to upgrade the turbo to get more power, but with the supercharger you can only upgrade so far. Once you get the smallest pully your stuck.
Heres a kit for a reasonable price.
Turbo-Kits.com - 95 - 99 Nissan Maxima Turbo Kits
This kit uses a small turbo that will help you produce about 6 PSI. Without doing some major work on the heads and engine, 6 is all you are going to want to push into the engine so you dont blow it! I have heard of people pushing up to 8 but they are lucky they havent caused any damage yet. 6 will take you maxima just a hair over 300 HP which will be fun and turn some heads!
Here is a sight to help you do it, get some stats and info on the whole process.
HLH0501 Turbo Maxima Resource
If you decided to stick with a supercharger the same 6 PSI applies. Just be careful when using forced induction on a high compression engine.
If you have any questions just ask. I've done a lot of research on this.