Hi Craig. "Huge logistical nightmare" sounds about right - I really think this might be better planned for next year, giving time to do it properly if there is enough interest, and avoid clashing with the RB Race. Don't want to dampen enthusiasm, but if it's going to happen it should be propely planned and publicised.
Here's another thought for you. How about making it a regional event? Maybe even a progression around the coast .... something like carrying the Olympic flame with a token being passed from one participant to the next as it works it's way around? That way, those people who would like to join in can do a local leg and be part of it if that's all they can manage, and anyone who wants to go further - including all the way around - could do that.
Wish you luck with it. Might well be interested in joining you for a section around either East or West of Scotland if you can make it happen.