I think it's the right step to go for Patek. Apart from Nautilus and Aquanaut, a steel watch from PP is very rare.
As this 5960/1A either white or black is not very popular, PP may discontinue in order to increase the collector's value.
PP did the same game so many times. Due to the fact, that the 5960/1A is not popular, there are not that much examples out there. If you could get one, take it. In some years, the people will realise how beautiful this model is, and demand especially for steel one will increase dramatically!