A good touchscreen monitor recommendation

I am looking for a touchscreen monitor in the $200 to $300 range. I currently have the computer hooked up to my tv via HDMI. I want to keep both my new monitor and the TV hooked up to at the same time.

I have an AMD Radeon HD 7570 2GB GPU. It has 1 HMDI and one DVI output, and one that looks very similar to a HDMI, but is slightly bigger. Any ideas what that would be?

I don't know if this third connection would be better than DVI, for I don't even know much about DVI, or what type of connections a touchscreen monitor would require. I also see that I have an optical audio out...don't really know what that is either, what would that be used for?

Everyone on here is usually so helpful, so thank you in advance for any info :)