HR Monitor suggestions

lmfbs

I'm in the market for a HR monitor (my parents graduation present to me). I'm tending to think that I want something simple and comfortable, that is versitile.

I've been looking at the Polar FT7, but my dad suggested a Garmin Forerunner. I understand that the Polar doesn't have a GPS.

Basically, I want to know:

HR
Calories burned

I'm unsure whether I want something with GPS but I'm thinking it's better to buy above what I need, even if I'm not doing a lot of running right now, I am planning on doing a 1/2 marathon in a few months.

What do you look for in a HR monitor? What features are important to you, and what HR monitor would you suggest for someone who's never owned one before?