Just be sure you get the right one for your needs.
As I understand it, the normal one (Event Processor) can process up to 10 events and store up to 2 variables, but I think that if you need to "chain" steps together to get more done then each additional step uses up one of the 10 events.
But I'm not certain that that's how it works, so you might want to speak with MIDI Solutions to find out. You can also download the programming manual for the Event Processor and get an idea of how it works by perusing the manual.
If you need to process more than 10 events and/or store more than 2 variables, the more deluxe version (Event Processor Plus) can process up to 32 events and store up to 8 variables.
So you might want to get the more deluxe version, even if it might be a bit of overkill for your current plans, if only so you'll have "room to grow."