Speed and loose weight

I want to loose weight, and every night I should go biking for an hour. I want a odometer to indicate the speed and time. I hope it can effectively help me monitor my progress and improve my endurance. I have found two models:
http://www.tinydeal.com/waterproof-m...6--p-8722.html
and http://www.tinydeal.com/multifunctio...6--p-9729.html
I do not know how to recognize a bike odometer good or not. Moreover, I don’t know the exact difference between these 2 odometers except that one is water proof and the other is solar powered. Both of them can tell me the riding speed, mileage and time cycled. but the second one has more functions like thermometer, auto lamp and stopwatch. but it is more expensive. So which one I can choose? Could you please offer me professional advices?

not a professional, but some here's some goober tips

wouldn't bother with those 2, cheap electronics, I'd get a well known brand name, cateye etc
Cheap electronics and the great outdoors don't really mix.

http://www.chainreactioncycles.com/C...CategoryID=250

depends on how serious you are about training/loosing weight, but in an ideal world, get one with a heart rate monitor too, it will give you calories burned etc and can be used for serious training too, knowing what zone you're in etc
You normally have to be exceptionally boring to do this, but I've seen normal people trying it too..

but if you just want speed, distance, time etc etc
I'd go with a basic cateye

for lots a sterling advice, your local bike shop, the bike rack (cabinteely), sprocket cycles (bray), eurocycles and eurobaby (longmile rd), etc etc

Jesus wept, I know times are hard and all but for feic's sake the difference in price between the two is less than a Euro....!?!?