If you can spare the RAM, i'd stick the world on a ramdisk (I did when hosting a MC server and it makes an appreciable difference versus the terribleness of disk IO)
You'll also want to look into making sure the save data is persisted to durable disk across reboots/power loss.
Of course you will probably want to incorporate something that copies the ramdisk contents to somewhere a little more permanent ever so often, set an interval you're comfortable with losing data within! (but given the huge improvement i'd say it is worth it!)