I would recommend looking at these EZXs:

http://www.toontrack.com/product/americana-ezx/

http://www.toontrack.com/product/indie-folk-ezx/

http://www.toontrack.com/product/the-classic-ezx/

http://www.toontrack.com/product/vintage-rock-ezx/

These above kits have a laid back feel. Most kits can sound laid back if you feed it laid back MIDI.

Here are some Toontrack MIDI more on the simple side:

http://www.toontrack.com/product/backbeats-midi/

http://www.toontrack.com/product/basic-rock-midi/

http://www.toontrack.com/product/basic-rock-fills-midi/

Also, keep in mind that with the Edit Play Style function in EZD2, you can use the ‘Amount’ and ‘Volume’ controls to make a MIDI groove simpler or more complex than it was originally. An ‘EZ’ way of making the MIDI you want from the MIDI you already have.