+1 on Ruthven.
Wear boots for approach at this time of year, as approach is boggy, and take your best skin, as rock is pretty coarse. It is very exposed and dries quickly, but downside is it can be fucking baltic up there at this time of the year, especially if it is overcast and/or breezy.
Saturday looks a bit pants, but sunday might be OK.
Best get in touch with your friendly local UKBer (richieb) who will be able to give you a better idea and alternative suggestions (like his woodyboard!)
As said above Brin might be OK, not sure how quickly it will dry this time of year. Likewise there are a few things at Duntelchaig which I think dries reasonably quickly, but is a bit more sheltered than Ruthven.
