Switch and record with one iMac?

I am planning on purchasing an ATEM-1 for handling live video mixing/switching. I will be using an iMac to control the ATEM-1. Can I also record the component program out of the ATEM-1 on the same iMac using something like the BM Video Recorder USB interface, or is this asking too much of one iMac? The video is recorded for upload to a website. Trying not to spend too much more to get an easy, web-friendly recording solution. We don't need to stream live, just want a workflow that will yield a video file at the end of the event that we can easily upload. Ideally, the solution would allow us to record at a lower resolution since all the live switching will be 1080i and we don't need that full resolution for the web version.

Yes, this is possible. The ATEM control panel software actually has built-in support for capturing over a BMD capture device, and I believe it supports scaling (I know Media Express does)

The control software is a very trivial load on a system, it just sends and receives very small network commands