Cycle computer advice

Burt25 Posts: 117
edited November 2012 in Road buying advice
I want to add a computer and cadence sensor to my bike so I can monitor my progress or lack of. I currently have a garmin forerunner 305 and I have an iphone. Question is should I get a bike mount for the garmin along with garmins cadence sensor or use strava on the iPhone and buy a bike mount for it plus an ANT sensor?