I have a Stihl FS-85 trimmer that you can put other attachments on. I have a power scythe and a hedge trimmer. Today I bought the pole pruner attachment for it. Its not quite as long as a standard pole pruner, but it does the job.
Make sure whatever you buy has a auto oiler on it. A lot of the pole pruners out there have no oiler and if they do you have to flip the head over so oil will drip out. Since you wouldn't be using everday a multi-attachment tool might be your best bet. If not just get a fixed shaft pruner.