Check out the Wahoo RFLKT.

It is around $80, and it pairs with your phone, using the phone to do the heavy computational work and it is just a (very) configurable display. By itself it does nothing, you work off the phone, all the data is kept there.

You can use any ANT/BT heart rate monitor, and it uses GPS for speed/distance or you can get one of the combined speed/cadance units from Wahoo if you want more accuracy.

The phone stays tucked away in a jersey pocket or a bag on the bike.