Hi Jane,
We have a 7 meter campervan, so you should be fine. I think most campervans would have no problem, but the reason I am a little less certain for caravans is that although the hardstandings are fine for vans, manouvering into them might be difficult if the other sites were full and you were towing a caravan. There is one site that looks ideal for caravans though, where you could drive in and easily reverse into it, so I guess if you get there early....!!!!
If you like bird watching, it is great. They come and use the lift off the cliff and hover and swoop in front of you. It's a delight. The view is fantastic too - out over the Loch and the sea not over the fish factory! Might be tricky in the wrong wind though - westerly gales and you might be somewhat exposed and facilities are rudimentary.
If you are looking for off the beaten track sites, another gem is Badrallach Bothy and Campsite on Little Loch Broom. We got our 7 m to it although we had to be dragged out (the site entrance is steep and it's easy to dig into the soft gravel). Worth it though, fabulous site, great for walking and just so deliciously remote and quiet. Hookup here and a lovely clean toilet and shower block.
Les