Sean,
There are parts of river that we call association water in Scotland. These are usually stretches owned by angling clubs or associations. If you are going to be in Scotland for a year, you could enquire about membership to one of these associations for one season. Some have waiting lists, others do not.
Some of these association stretches offer tremendous fishing for the money(usually £50 - £200) per year. The downside of it all is that, when the fish are there they will be busy; not as a rule but in general.
If you like more secluded and private fishing you have to pay a bit more. Often the very top beats are let well in advance and a minimum of a week must be booked. However, good fishing can be had on day tickets provided you get the correct conditions.
My advice would be to try and get a membership to a fishing club or association for your bread and butter fishing. You can then periodically treat yourself to fishing more private, productive beats.
Extended searching on the net should provide you with details of clubs, associations and private beats. I don't know if I'm allowed to supply details of these associations on this site.