I was in Glencoe a week ago and would say that anything in the west that's prone to being wet will definitely be wet.
Alternative option would be to drive to Skye via Perth and Dalwhinnie (drive time is much the same) and stop off for the classics at Upper Cave, but that's probably going to be wet too.
Or, for an extra hour's driving (much less of a diversion than Tighnabruaich or the Anvil would be), go via Inverness and stop in at Brin or the Camel. Both have a good selection of 7s and a few 8s, and I would guess might be more likely to be dry.