I'm in a similar situation to the OP whereby I am looking to potentially hourbuild in Scotland in the near future. I don't know if any of these aircraft groups would be willing to rent their aircraft out for a block of hours (60 or so). I am not too sure about buying a share in an aircraft though. I guess primarily as I have never done it before but also as post hourbuilding I would be busy completing the CPL MEIR and wouldn't really have the available time to fully utilise a share in an aircraft? In terms of owning a share, are you allowed to take the aircraft away for extended periods e.g. a couple of weeks?
I'd be interested to hear if the OP did manage to secure an aircraft to build time in Scotland, or from anyone else who managed to do this.
Thanks