HRM-which do you suggest?

I have a polar ft4. It was around $60 on amazon and it's easy to use.

Lots of people like the Polar FT4. I have a Polar FT7 and love it -- it's right around $100.

If you're interested in a GPS for tracking miles (biking, running, etc.) Garmin makes some nice ones buy they are a little pricey.

Make sure that you get one with a chest strap -- they are much more accurate than just the wristwatch styles.

I have an Polar FT7 and I love it. I got it for about $70 on eBay and I know Amazon has it cheap, too.

It's more than worth the price as well, being able see my heart rate during a work out allows me to know whether or not I should go faster or calm down (it beeps when you go above your upper limit). The Polar FT7 also has a neat feature that displays if you're in the heart rate zone that burns fat or increases endurance.

The chest strap takes a little getting used to. I sometimes have to loosen or tighten it depending on my work out, but it's worth it for a more accurate reading.

TL:DR if no one buys you a HRM, get one. Especially a Polar FT7.

Polar FT4 or FT7 should work out just fine for you. Both are easy to use/set up and the only real difference is price and a few other features.