To me, lenses are liked my kids. I've known them well, for example, what f-stop to use to get the maximal DOF w/o significant diffraction.
I think you will not go wrong with either #1 or #2. You know your comfort zone. I don't think you will get much different quality between the 50/100mm and 35-90mm. Zoom can be very helpful especially sunrise/sunset when time is critical. The HCD 35-90mm is the best zoom in this range for me. When it's on the tripod, it's not that heavy
I've found the 1.7 TC is also very useful and it's very light. Sometimes 1% of your photos may turn out to be a winner and you will regret you haven't been well prepare! At least I know Graham has the same philosophy from his reputation
Graham, if you read this comment, I'd like to let you know you are one of the greatest guys at GetDPI!
I hope you have a wonderful trip and am looking forward to seeing your pictures.
Best,
Pramote