No Grand Seiko, vintage or otherwise
Something tells me that you are not the person who will stop with one watch, Daytona or otherwise. In which case you might want to consider starting with the Omega, as it may allow you additional watches sooner. If you save up for the Daytona for several years (laudable) and then have an itch for more, which you will also need equally long to scratch, that may be frustrating.
As I said, may - you will know yourself best and often in such cases the decision has already been made in your heart of hearts 
In any case welcome here and we're excited to see how your journey progresses!