Blimey, it’s been over four years since I posted my original question, time for an update I guess.
In the end I went for a pair of 32 Marathon Plus. I know some say these are a bit slow & heavy, but as Rod Marton almost said upthread, we’re also a bit slow & heavy. Anyway the good news bit, not a single puncture! Whether that was simply down to good luck (that's ruined it hasn't it) or tyre technology is improving I don't know, but eirther way for a, err less than light weight combo the Marathons have done the trick.