First, if your headtube was made for a 1" headset and foirk, you must stick with 1". Other than having a frame builder remove and replace the headtube with a 1-1/8" one, there is no choice and that option would be absurdly expensive.

As long as you have to replace the fork, you might as well go threadless all the way so option 1 is my recommendation. You will have to buy and install a threadless headset but, overall, the new set up will be lighter and 1" threadless headsets are not that expensive (at least not if you avoid Chris King or similar).