The only boat access I can think of is either a little west of the dam, or a mile west of the bridge across the northern arm of Quoich. This side of the loch is on the Wester Glenquoich Estate, so I guess they might be worth hunting down and asking, but sticking that into google has got me nowhere other than a holding address in Blair Atholl;
http://www.whoownsscotland.org.uk/property.php?p=1474Problem is that nobody lives around the loch and I can't remember seeing any boats stashed, so any boat is likely to have to be transported in for you on a trailer (prob from somewhere down towards Loch Garry, and I'm betting that's going to be costly. Might be worth a bit of time searching though. Or hopefully, somebody else is better informed than me!
Your approach is logical, but you might be stuck with hitching up the road from the dam to start, crossing the rough ground round the loch (improves after Glen Cosaidh I think as the old road is above water there!!!) and then up.
I want to camp at Lochan nam Breac before I die, so my own approach would involve overnighting there, and a slow exploration over a few days. Annoyingly, the only one I've done is the one in the middle S n C (thanks to conditions for the western end, and dodgy knee on Gairich). So, I'd be doing the west end separately (maybe by canoe), then possibly S Mor etc from Kinbreak on another occasion.
You won't avoid bogs on any route!
Those from Gairich to the dam are pretty infamous too...