In reply to Rob Exile Ward:
4 hour drive seems about right. Glasgow Airport helpfully leaves you on the right side of Glasgow as well. Long, slow road from the Glen Garry turn off into Kinlochhourn though, worth 40 mins on it's own at least?
I've usually done the coastal walk in about 2 and a half at a pace, 3 hours more easy going.
Risky with midges but could be ok. The weather could be settled enough that they are ravenous right up to the summits. There isn't really a max altitude in itself in my experience, it's more to do with whether the wind and sun sees kindly enough on you to keep them away. But you have Barrisdale bothy to get some sanctuary should the worst happen. I also think a head net (and long sleeves) is simply one of the best purchases you could make for any Highland summer camping trip.