Did not know about RM furnaces - thanks! Seeing as I've got 8 chests with 54 slots each (432 slots total), each slot can hold 64 RM furnaces (27,648 furnaces), and each furnace is worth 2,514,952, I've got room for 69,533,392,896 (~70 billion EMC) worth of materials before I fill up. At a rate of 1.3 million EMC per minute, it will take roughly 53,846 minutes = ~897 hours = ~37 days before I fill up on RM furnaces in all my slots. (Someone can double-check my math there if you're as nerdy as I am and have free time).
Is there any good way to keep track of the total amount of furnaces/EMC I have, though?? I don't know Tekkit well-enough to know whether or not that's a possibility (other than just checking by hand).