Make your own with a 2x4 and some coat hangers. They're kind of unsightly, but they work really well. The one I have is similar to this, but without the reflector and everything is bolted to the wide side of the board instead of the edge. There are other designs out there that are simpler if you want to do a quick google. These antennae can be mounted in the attic. For hitting multiple TVs with one antenna, a UHF splitter should do the job.
If you already have cable or satellite coming into your home and hitting multiple TVs, there's probably a splitter in your attic somewhere. You'll have to figure out if it's the right kind, but if it is and your antenna gets good reception in your attic, you should be able to just connect the antenna to it and send signal to all the TVs you already have hooked up. If it's the wrong kind of splitter, you can get the right kind of splitter to replace the existing one and do the same thing. Depending on the length of your cable runs and the level of reception you get with your chosen antenna, you may or may not need a signal booster.
If you already have cable or satellite coming into your home and hitting multiple TVs, there's probably a splitter in your attic somewhere. You'll have to figure out if it's the right kind, but if it is and your antenna gets good reception in your attic, you should be able to just connect the antenna to it and send signal to all the TVs you already have hooked up. If it's the wrong kind of splitter, you can get the right kind of splitter to replace the existing one and do the same thing. Depending on the length of your cable runs and the level of reception you get with your chosen antenna, you may or may not need a signal booster.