EX EFI is somewhat unique because its "EZ". The others you mention (and FAST) have systems that completly control fuel and spark but aren't so EZ.

I think your ignition should be fine. A MSD ignition may run a little better, especially at idle and low load, but what you have should work fine... especially if it is already dialed in for your engine. Its better to change one thing at a time anyhow. I assume you have the fuel system covered with a high pressure electric pump and suitable filter and regulator. You'll need a fuel pump block off plate available from Mancini and just about everybody else to cover the hole left by removing the OE type pump.