Just did a search in your area (Thurso, Scotland) and they have an audiology department at Dunbar Hospital, in Thurso. If they are not able to make impressions, you can also call and find out in one of these hospitals:
This service is available in the following hospitals (most of these do not look too far from you)
Raigmore Hospital (Main base)
Caithness General Hospital, Wick
Dunbar Hospital, Thurso
Lawson Memorial Hospital, Golspie
Mackinnon Hospital, Broadford
Portree Hospital, Skye
Belford Hospital, Fort William
Community Clinic, Fort William
Ross Memorial Hospital, Dingwall
For people living in Argyll and Bute the contact is
Audiology Department
Lorn and Islands District General Hospital
Glengallen Road
Oban PA344HH
Tel : 01631 788993
I found this out via the website link: http://www.nhshighland.scot.nhs.uk/Services/Pages/AudiologyDepartment.aspx
If any of these places can create impressions, you can have them use the SCS impression instructions (http://www.sensaphonics.com/Ear%20Impressions%20How2.pdf) and can order online as well (http://store.sensaphonics.com/ProductDetails.asp?ProductCode=Shure+Sleeves). You can email Claudia at Sensaphonics (saveyourears@sensaphonics.com) and she will be able to help you out with ordering, shipping, etcetera. You can also PM me with any questions as well if you'd like.
If you decide to go custom, good luck to you!