In reply to xyrandus:
Scotland's weather is very variable. And so is the quality of climbing.
You can find horrible weather and poor climbing conditions in one area, yet 100km away the weather and climbing is great. Or even 50km away.
I think the best advice I can give is be flexible with your plans. Have some ideas for Ben Nevis, but also some ideas for the Cairngorms, and maybe some ideas for Torridon.
And even have some ideas for what you would do if you came to Scotland and there is no safe climbing to be done anywhere - it is not unheard of to have a massive thaw mid winter which leaves little snow anywhere, and that snow is dodgy.