Upgrading

[indysteel]

I'd add the Soma Double Cross or even the Smoothie if you can get away with 28cc tires. I have a Jamis Aurora for touring and could recommend that as well, but I'm not sure the frame is as nice as the other suggestions you've received.

[jezbael]

Thanks for the recommendations!

How does a person know what size of bike to get? I don't seem to recall there being an option when I bought my Kona, but the Surly's list different sizes.

[Owlie]

What size is your Kona? Does it fit (ie, you don't feel too stretched out or cramped)? There might be a sticker on the seat tube somewhere that will tell you the size. If not, grab a tape measure and measure from the center of the bottom bracket to the top of the seat tube. You can use this as a starting point, even if it doesn't fit. If it's too big/long look at smaller bikes.
Also, what's your height and inseam? I'm about 5'7" (little shorter, but not much), but my inseam is like 31.mumblety inches--short torso. So I need a bike that's a size smaller than my inseam alone would dictate so I get the right top tube length. Surly has oddly long top tubes--I'd need a 46cm to get the short reach I need. (For comparison, I ride a 50cm-equivalent Giant, I need a 51cm Cannondale and a 54cm Specialized, all women-specific.)

Go test some out. A bike shop can give you a rough estimate, and if it's a good shop/employee, get you on the right size bike.