Thanks chris63 and Deckter , I appreciate the input. I did see it priced by an online travel agent before making the post but didn't want to go ahead with it, and was thinking of using a travel agent as a last measure if I couldn't get it working! It's just a shame because before we decided to go with Greece, we were flying back from Rome and it was suoer easy - we found some good flights on SQ that were great and worked perfectly, and could be booked through the SQ website and whatnot, but as soon as we went to add Greece, it's made things a whole lot harder! Even more so because like you said, it can be priced and found on Google flights which is annoying!

Also Deckter, I didn't quite get what you meant by this part - though again, this could just be my inexperience showing:

Is this not already an open jaw flight? If not, what would an example be of an open jaw? If there's something I can do to change it and book it directly I'd be down, and even if not, I'd be down for learning, as although this is out first major holiday, we don't plan on it being our last, that's for sure.

I'll keep playing around with things in case we find something that works, but otherwise I'll talk to a travel agent and see if they can find the flights and make the booking for us :-)