Thanks for the follow up Scott,
Ok, easy it is!
The roof mount is ideal. You'll have a couple choices whether you mount on via a tripod, eave or chimney mount. The chimney mount can work well if a good reception location due to being able to avoid drilling holes.
Your coax run isn't too bad. 120' maximum. If I were putting the setup together, with those runs I would not run a preamp. I get uneasy when I have a 57 db signal and I'm pointing really close to it with a preamp in line. Initially, I would run the coax straight off the antenna to a splitter, then to your TVs. You have a nice amount of signal. I would operate on the first test with idea that a C290 would put plenty of signal down that far.
I have a RCA ANT751 small antenna running without a preamp on my second coax drop. It puts signal down 100' of coax then splits to two TVs and 20' and 50' additionally. My signals are comparable to yours for my locals. Signal is fine and reception is rock solid at the farthest TV. If it turns out not to be enough and you have too much loss and unreliable reception and aiming doesn't cure it, I'd be inclined to purchase a distribution amp. A channel master 3414 has a good reputation. They sell them in 2, 4 and 8 port options.
http://http://www.amazon.com/Channel.../dp/B001PI09SE
I am in the camp that offsetting your losses with a distribution amp in this setting is the worst case scenario and is preferred over juicing up that 57 db signal.
You have a variety of viewpoints here as to what to set up and how to do it. GUM advises you well on the multi-directional setups and how with your signals that is not the right antenna for you. Teleview and I both agree a single all-band antenna pointed at Grand Rapids is your easiest and quickest way to reliable reception.
Lastly, you are right Lansing has duplicate affiliates. In some cases people between markets like to have the option for both sets of channels. That gets a wee bit more complicated. However, an all-band antenna about magnetic 300 should get you in the door.
When you do your first tests, run only the lead off the antenna into the back of your TV. No splits or anything - just straight coax directly from the antenna. Then do your channel scan. You'll know how well you do are doing. If reception is acceptable, then add splitter and additional coax runs monitoring system performance for problems.
Best of luck in your decision!