busybox+kernel = NAS server?

[badeguruji]

Hello,

I want to build a home NAS server: level of importance:-
1. reliability of functionality.
2. speed.
3. Cost (least but yet very important)

I am beginner and have been researching web for at least 2 months. I have read about eCos, embedded linux, hardware architecture, software available (like freeNAS, Openfiler, Linux, busybox etc.)

How difficult is it to build something like this:

linux kernel + busybox + NFS +SSH +SSL +DNS+DHCP servers etc.

how can i do this? can someone please guide me to a document on web with step by step directions to add only the servers i need to add to the linux kernel?

Also, will it be more efficient to use a strip down ubuntu/debian server? (and how?)

confused, please guide.

thank you.