The Garmin Dakota 20 may be better suited for dual use.. Do not even consider to the model 10, it does not have a microsd card slot which is necessary for the the extra maps.. The dakota 20 supports the use of Garmin Heart rate and cadence options.
https://buy.garmin.com/shop/shop.do?cID=145&pID=30926
reviews:
http://gpstracklog.com/2009/10/garmi...20-review.html
http://www.gpsfix.net/gamin-dakota-2...t-impressions/