A 300 pound load?

The tires I have on my 700c bike are 32c, but they are an actual 32, which means they
are larger than most tires claiming to be 32....

You want at least a 32, a real 32, IMHO.

The next step is what sort of tire you want.

The Contact strikes me as an odd choice, what do you want in a tire?

I do lite touring, so I can pick a tire that is big, but lively, like
my Vittoria Rando Hypers. The tire is a bit schizophrenic.
While I like it, it is a bit too eager for me. It's a really big performance tire.

So what are your top priorities in a tire.

http://www.bikeradar.com/gear/catego...ur-hyper-33552