best way to increase NFS file server performance?

[Jurvis LaSalle]

All:

	Sorry for the homework-like question, but I am looking to increase the 
performance of our NFS file server.  We have ~ 120 users but rarely 
have more than 25 concurrent users.  We currently have RHEL v3 
installed on 2 33GB 10K rpm SCSI  disks in one LVM volume group.  I'm 
looking to get the most benefit for our limited budget and some 
purchases I have considered are:
		- Gigabit NIC - would I see much/any performance gain considering 
this is a 100MB switched ethernet LAN?
		- a 3rd SCSI drive added to the volume group ( + striping? )
		- more RAM

 From which would we see the most bang for our buck?  I suspect adding a 
drive and setting up RAID 0 as described here 
(http://tldp.org/HOWTO/LVM-HOWTO/recipethreescsistripe.html), no?

Thanks for any suggestions/comments,
Jurvis LaSalle