if you follow the advice that I gave you, and install it as I recommended, you aren't going to have to screw around with returning antennas: it will work: if you try a single antenna solution it WON'T work. Most people find that Solidsignal.com has the equipment that you need and has very competitive prices. You shouldn't use a chimney mount if you burn wood, but an eave mount or a tripod mount on the roof will work well for you. This isn't all that hard: don't make it harder than it actually is. Here is a good installation guide to help you:
http://manuals.solidsignal.com/AntInstallGuide.pdf