You sure asked at the right place!
The worst Mondays are the first Mondays after a vacation...
The established suppliers can make Pd gold for you easily. Do not
use ordinary white solder it is usually made with nickel. The color
would differ, and a Ni allergic reaction would be a small
Palladium white gold is blended, cast and annealed at higher
temperatures than what you are used to from silver. I suggest you get
gold already mixed, just melt and pour your own bars to roll or draw.
Pd gold is soft enough to work easily and is not subject to fire
cracking (cracking while heating up for annealing or heat treating).
Of course it will take a little getting used to. Grain, Sheet and
wire are available, and at least from my employer, Pd solder is
available as well.