I'd recommend a Garmin but I'm not sure what your price range is. I started out with a basic CatEye that did speed, distance, etc but didn't have heart rate or cadence. Then I got a CatEye double wireless that had heart rate. Then I was tired of not having more information about grade, elevation, etc so I sprung for the Garmin. I found a barely used Edge 705 for $325. The 305 can be had for cheaper and you will most likely not be wanting to upgrade for quite some time. I probably wouldn't recommend the CatEye double wireless because power lines really interfered with heart rate information and you can't mount the speed sensor on the rear wheel because it can't transmit far enough to read it.