I was in simlar type of problem to
My iMac does not have internal BT, so i would need a USB add on.. which after i took my keyboard away would take me down to 2 USB ports, and i had a Shuffle, "dock" iPod cable, AirClick USB and FlashDrive(my printer is on my bro's Mac, i print wireless) and then my AirClick started to die, so i put it aside and got the BT Mouse and Keyboard, and it looks Sharp! i really nice, well worth the price.
For you i say
Get a BT mouse adn Keyboard, hook up the printer and iPod cable to the back, and then you have a 3rd open USB port for the Flash Drive or something else
But Apple reall should add 2 more USB ports