Hi sorry can't comment about a private villa or gulet but I can recommend a super hotel in the Kaya Koyu area that does have a pool. It is called Villa Rhapsody and it is located in the ghost village of Kaya Koyu just outside of Hisaronu and is about 15 mins to Olu Deniz. Jeanne the Dutch owner along with here husband are very helpful and can probably arrange for different trips like boat trips or day tours for your family members to keep them occupied. Here is the web site and you can check it out.

http://www.villarhapsody.com/

this page shows the different daily excursions from Kaya Koyu

http://www.villarhapsody.com/excursions.htm

If I where you I would hire a gullet but not villa. It would upset my family, and look as if we escape from them. If I rent a gullet I would explane it like I adore gullets and so on If I find a link for gullets I will let you know. Have a nice wedding!

Thanks for all the advice
We've booked a one day boat trip the day after the wedding for us and all our 60 guests as part of our wedding package
I'll have a look into the other places suggested.

Yes just a few days - ideally 5, but we'd be happy with 3 or 4. We just want a bit of time to have a break on our own. We'd have to go back to the Telmessos at the end of the week anyway to get our transfer back to Dalaman.

Why not book into the Oyster Residence in Olu Deniz for a few days? Its supposed to be very good and there are no kids under 14 so not a family place.
http://www.exclusiveescapes.co.uk/destinations/property/oyster/detail/