I was in your situation a few months ago, and ended up getting the Airport Extreme base station - mainly because we have a desktop computer. If you need to have a wired connection you'll need the base station, which has both a WAN and LAN port.
The USB printer port is really handy. Previously we had to leave our Windows box on all the time because it was acting as the print server. This was sub-optimal also because the Canon i550 drivers for Mac basically don't work with a remote SMB printer. But the USB port on the base station is treated as "local" by both Macs and PCs (a bit of monkeying around is sometimes required on the PC though).
The main problem i can see with a non-Apple base station plus the Airport Express is you might not be able to use the AE as a repeater/extender for that wireless network. I'd be curious to hear if vkapoormd has his AE working with the D-Link router, or independently.