Make sure to sample some of the local whisky while your there. Did a western isles whisky tour few years ago. Was excellent. Arran is also nice, go there regularly but yet to take the mavic, spring hopefully.
MOD only publish timetable for 3 out of the 20 low flying zones, these 3 are tactical training areas (TTA).
On a closer look the timetable is pretty pointless unless you want to go see the aircraft as it states other operations may be carried out on days with no schedule.
The schedule for these are here,
Military low flying: RAF operational low flying training timetable - GOV.UK
Where you are wanting to go is not covered by one of these TTAs, but a standard low flying area LFA14 which covers pretty much the whole of Scotland.
I'm planning to do some of the western isles in the summer, flying there won't be a problem.
Here's some more info from MOD, at end of leaflet is a telephone number you call and get a daily forecast of low flying for all areas.
https://www.google.co.uk/url?sa=t&s...0A3cQFghTMAQ&usg=AOvVaw0C6WANdviccbHHi6HQ7Cmk