Thanks for all the information.
Unfortunately the accommodation / flight isn't available for the only time we were able to go this year
Good news

we are going to book for 2 weeks going next September.
Before we book, I remember reading in a brochure last year that you could do a twin centre holiday with a week in Symi followed by a week in Halki (or vice versa) however I cannot find this on offer in any brochure for next year.
Does anybody know a company that still does this ? I have tried several travel agents but none have been able to help.
I have also looked in to going DIY but to be honest the overall cost is MUCH higher than just booking a single island stay package deal to either Symi or Halki.
Example for 2 weeks -
Accommodation = £650
Flights from GLA = £410
Return taxi to port = £38
Ferries = £20
Total £1118
A 2 week package to Anastasia Mouragio with Olympic £690.
£428 less than booking DIY
Any thoughts would be much appreciated as I would like to book the holiday this week if possible.
Thanks again
Graham