Sites for Ben Nevis
The site in Glen Nevis is excellent (the link is in an above post): a good shop, good service blocks and OK food/drink available on site with bar food and restaurant food options. The slog up the Ben starts 300 yards from the site opposite the Youth Hostel. The path is easily followed in bad mist but take a good map to get the bifurcations right.
I did it once overnight to watch the sunrise from the top but there was too much rain cloud.
There is an excellent Inn (Ben Nevis Inn I think?) 1/4 mile from the site and at the true bottom of the Ben Nevis path (the path from the Youth Hostel joins the main path about 1/2 mile from the real start of the path where the Inn is). The beer in the Inn is very good and the food is of a high quality. There's no point in going into Fort William for food if you want quality: the Inn is nearer and better. Quaintly rustic with a mix of tourists just got out of cars with their freshly ironed mountain clothes and climbers having just done the trip, manky knackered and very thirsty.
A word of warning, though: the winds coming down the glen can often be severe. Nomatter how well you secure your awning, it will not survive - so wind it in when away from the van.
Enjoy