West Highland Hunting have a very good reputation in the UK. The Head Stalker (PH) Niall (pronounced Neil) Rowantree is a well renowned expert on red deer, see the likes of
.
Most red deer stalking in Scotland let is on free range and on the open hill. WHH happen to have a deer park (a rarity) but just confirm you want to stalk the 'open hill' with them, this is open moorland in the mountains.
The stag quality on 'the hill' is not as good as forest stags or those from forested areas in other parts of Europe as the feed on the open hill is poorer.
Also, be aware, here in Scotland we cull bad heads as a rule, we take a few very old trophy heads. WHH have some of the biggest wild stags in Scotland mainly because Ardnamurchan sits on a penninsular and thus the warm Gulf stream waters surrounding 3 sides of it ensure it gets a longer grass growing season than most places in the country.
Most Highland estates offer stalking but get booked up so look to book now for the rut (end of Sept until end of season 20th October.) An agent who has been operating in the Highlands longer than anyone is
http://www.kiltarlity.com/ who can arrange driven or walked up bird shooting too.
Alternatively you can opt to book direct with an estate such as
https://www.alvie-estate.co.uk/ or
http://www.achnacarrycountry.co.uk/stalking.html
Breathable waterproofs are advised but it can still be warm in October so a shell layer can be carried in a bag with your 'piece' (lunch.) 10x binoculars are advised. All estates offer a borrow or 'estate rifle' - otherwise popular calibres include 6.5x55, .270, 7x57, .308. Average ranges are around 150 yards and less in the rut.
Good luck!
Nick