iPhoto, Aperture, Elements, and Topaz DeNoise...

New to Mac. Got a 17" MacBook Pro (2.4 quad core, 8GB memory, 750 GB hard drive (7200 rpm). Had been using Photoshop Elements on PCs for years, so had to have Elements now too on the Mac. Got the editor only version from the Mac App store. Also purchased Aperture from the Mac App store. I have a license for Topaz DeNoise, so I plan to install that on the Mac. Questions...

1. Where would Topaz DeNoise fit into the above? As a plug-in for Aperture? As a plug-in for Elements?

2. Does iPhoto still fit logically into the above somewhere?