Personally, I don't think that the OP really knows what they want, or they want the best of all worlds without compromise.
I can't help but feel this is another classroom based scenario.
I mean 5GB on an actual host, seems kinda silly to me?
No real mention of what these hosts will actually do or what load the NFS server will be encountering or even data set served.
Not tryin to flame here, but it just doesn't seem serious.
And if this is real, then the OP needs to try harder and sell the idea of spending more $$$ to the higher ups.
- aurf