In reply to johncoxmysteriously: A few boat/hill suggestions in this UKH article form a year or two back:
http://www.ukhillwalking.com/articles/page.php?id=3894 ...though I see the more obvious ones have been mentioned already - Ladhar Bheinn via Loch Hourn, Ben Alder (and more relevant to Loch Ericht, Beinn Bheoil - no it's not a track all that way down the loch)...
I'll add Loch Quoich as a potential route into Knoydart on top of Nevis, Morar and Hourn - it's clearly good for all the munros from Sgurr na Ciche to Gairich and could be used to access Luinne Bheinn etc too.
Mullardoch is more convenient access than Monar, if you're up that way - and at its head there's a brilliant round of Gleann a'Choilich which takes in all 6 munros from Fionnlaidh to Dheiragain - quite a weekend expedition with the 13km paddle each end too. Very natural boat route, not contrived at all. To reach the south side of the Carn Eige range you might also consider Loch Affric too, though it'd be a novelty trip since the track is so easily cyclable. Ditto for Mullach Fraoch Choire etc by way of Affric - doable but hardly necessary.
You could try the Fannaichs from the southeast via Loch Fannich, though again the bike option is a bit less faff.
If you can work out how to get your boat into Fionn Loch then A'Mhaidghdean etc are your oyster
Sure there's more...