Here is a link to the Glacier Park chat: http://glacier.nationalparkschat.com/phpBB3/
There are many great hikes in Glacier, but I find the better ones to be multinights. It can be difficult to find what you want in just an overnight if you don't want to do high mileage.
Not too many trails that follow a ridgeline in Glacier, but don't worry, the views are still great.
Cracker Lake would be a nice overnighter. Elizabeth Lake as well through Ptarmigan Tunnel, but the mileage and elevation gain may be more than you want. I would say the Highline Trail to Granite Park, however in August Granite Park has to be part of a multiday trip (unless you can find room at the Chalet).
Dawson Pass-Pitamakin Pass would be a great overnighter out of the Two Medicine area.
If you are looking at just overnighters, probably consider the Many Glacier or Two Medicine areas. Unlike the east side, on the west side you generally need a day to get high for the views.
In Waterton, you can overnight at Crypt Lake, which is a great hike. I don't think that there is a campsite on the Anderson-Carthew trail there, but it is another good hike.
Campsites are reserved, so check availability on the NPS site. Approximately half the sites are held for walk-ins.