Just for reference:
Stock wires - 1200 to 1500 ohms of resistance per foot
Ford Racing wires - 500 ohms per foot
Accel yellow 8.8 - 250 ohms per foot
Accel black Race Wires - 150 ohms per foot
MSD Super Conductor wires - 50 ohms per foot
Moroso Super 40 wires - 40 ohms per foot
Ohms is a measurement of resistance in an electrical circuit. The less ohms, the more power is transferred. Obviously, you want the least ohms you can get to make sure you get maximum voltage to your plugs, especially if you're boosted or hitting the nitrous. With high cylinder pressures, the spark can actually get blown out before the mix ignites, so you better have adequate wires.
RFI is radio frequency interference and can cause havoc with other electronics. Ever hear a buzz that speeds up and slows down with the engine?
EMI is electromagnetic interference and can also cause havoc with other electronics.
So you want low ohms, and high RFI and EMI supression. Check the specs of all wire sets and you'll see which to get.