One word, Apple!
Take a look at the XServe G5
Coming with a Unlimited connection license OS X Server can handle all your file/print server needs as well as do FTP, DNS, Mail and Web serving.
Applecare is cheap 3 years of support for less than $1k and the servers themselves are not all that expensive either, I'd recommend a dual processor over the single.
Dont buy Apple ram, That's where they get you on price.
With a built in 80 gig drive you can start small for your storage needs and grow up to three internal drives and possibly up to 100 external drives attached via FireWire.
Also there's the option of a xServe raid, 5.6 TB of space for 13k!
I'm presently involved with a project at my work to replace ~40 SUN Microsystems servers with 22 Apple xServe Cluster nodes, And 11 of those are offsite mirrors of the primary servers so in reality its 11 servers replacing 40+.
Also as it is there's so much spare cpu cycles I'm starting to share tasks on one server that was origionally tasked for two different servers and I still have loads of free CPU and RAM.