You are correct, sir -- the DCP-7030 is not network-capable. In order to share it across your network you'd need to plug it into one of your computers and share it via SMB.
The HL-2170W is wireless capable, meaning it has a built in 802.11b/g adapter. You could probably get by on an ethernet-capable device here, though. I've seen your office, it's not so big that you can't run a cable.
If you're still set on network capability but want that multi-function device (and don't mind paying a premium for all that functionality), there's the
MFC-7440N as well. At an MSRP of $319.99, it's probably the cheapest you're going to find that will do everything you want.