I have recently done some research and found out that one of the Garmin-units is the case. However they have a problem around the track point limit of 10.000 which means you need a possibility of downloading parts of your long distance tour along the route. Thatīs really a problem if you donīt have a laptop with you on the bike
The unit I first decided to buy was Garmin eTrex Vista C - it include Compass too. As you say, you need not the mapping functions. Then I think you should take a look at Edge 305 -
http://www.garmin.com/products/edge305/
Garmin has increased the track points to 13.000 - Great but it can be even better! However, you didnīt want that but I think they have developed the unit especially for biking with all the features we like to use - but believe it or not itīs without the Compass - Iīm really surprised.