I am assuming I need an HDMI Box with 2 outputs.

But does that mean I have to watch the same shows at the same time?

Is there a way around this other than getting 2 comcast boxes?

If not, could I wire both tv's directly to cable and when one is using the HDMI the other would just use the regular cable?

thanks in advance.

Splitting HDMI doesn't always work because of handshake issues, it would be easier to use component and split that.

"But does that mean I have to watch the same shows at the same time?"

Yes

"Is there a way around this other than getting 2 comcast boxes?"

If your TV's have QAM tuners in them you can at least get basic local HD channels by hooking the cable directly to the TV, if you want any other HD programming you need to use a rented box or cable card enabled tuner such as an HD Tivo.

"If not, could I wire both tv's directly to cable and when one is using the HDMI the other would just use the regular cable?"

You can run regular cable directly to both and just switch to the internal tuner on them vs whatever HD input you use for your STB.