Todd,
Since you need to solder something to a printed circuit board, keep in mind to not overheat it. The best way is to apply a thin layer of tin onto each part first, then solder them together. You should have no problem with tin-plating the PCB pad - any rosin-based flux is good. As for stainless steel, you need a more active flux. If you can't find something suitable, you can use even ZnCl solution (or orto-phosphour acid), but then wash carefully this part with hot water after tin-plating and before you solder it into PCB.