Serious answer: 15cm is an odd size these days, deeper than common road bars but well short of the 17cm plummet of a Deda Velocita. You've narrowed your options even further by insisting on silver and fitting a 26.0 stem
Solution: Deda Velocita, +10° OS stem. That gets the grips where they would be if you put a 15cm drop on your current stem, assuming it's -5° at the moment. Tweak the stem length to get the reach where you want it.
Serious answer: 15cm is an odd size these days, deeper than common road bars but well short of the 17cm plummet of a Deda Velocita. You've narrowed your options even further by insisting on silver and fitting a 26.0 stem
Solution: Deda Velocita, +10° OS stem. That gets the grips where they would be if you put a 15cm drop on your current stem, assuming it's -5° at the moment. Tweak the stem length to get the reach where you want it.