Best heart rate monitors..

Hello everyone,

My name is Jamie... did the great southbay tri on long island in june 2009... now I'm addicted to racing!
Signing up for the LI half marathon next May and doing the Great south bay again that June.... I figured this would be the best place to ask about heart rate monitors.... I have a standard one already... polar... gives heart rate and calories burned.... Howvever, this is what I need regaurdless of how expensive...

-Distance covered
-pace
-calories burned
-GPS(if able to be used for geocaching???)
-water proof
-actually works well in water(some reviews I have read have said the water proof ones dont work well in water)
-Track distance and pace in water


I have researched the garman 405, 305 and 310... I have also researched the timex ironman watch...

If anyone has any feedback on these heart rate monitors or know of one other than the ones I have listed ... your feed back will be GREATLY appreciated....

I have been doing a lot of researching but have gotten a lot of mixed reviews.... these HRMs are expensive.. I don't want to spend that kind of money without knowing its a good product

Thanks so much!