Cable TV / HDTV Antenna Question.

[shilala]

Here's what I have going on...
I have regular cable with a dvr at the living room. I then serve out just the basic cable to the rest of the tv's in the house which is more than enough. The rest of the tv's don't get any HD stations though. That's not a problem, really, but the story gets deeper...

I have an HDTV antenna that I use specifically to get local HD Stations from Youngstown, OH so we can watch the Steelers when they are out of market (we're in Browns territory here).
That antenna has a little gain amp right at the tv. In order to split that signal, I need another pre-amp, which I'm buying today. It's right here. I'll do away with the little preamp at my tv or give it to my father-in-law who needs it for his new antenna.

What I need now is a box that will take the input from the cable and antenna, do whatever it does with it, then give me a way to output it to my system.

All this will happen in a box mounted in my basement. There's power there and I have dedicated cables run to every device. They're all marked and ready to go. I have to pull some cable to the antenna and some more stuff to the ground floor, but I have the cable and tools and everything I need for that.
I just need to know what to use to mix these two inputs into one output.

Thanks, guys!!!
Scott