Hi people, just an update on this thread, I have just ordered a 2014 alloy synapse, disc, ultegra, 61 cm, which equates to a 60 top tube length, the shop will add a longer flipped stem which should do the trick for me. Took a long time to find one, one of not many (4?) left in Australia.
I will put 28s on it and work out the rest as I go. Very happy. Thanks for all your suggestions.