LOL! at even a foot more than Seattle, that's not an excessive amount of rain compared to some areas of the country. Atlanta, considered the peach growing capital of the US, averages around 50" annually....and that's spread out relatively evenly throughout the year. At least in the PNW, the majority of our rainfall occurs from late fall through spring, leaving our summers - and peach ripening season - pretty dry.

As long as the tree is planted where it has decent drainage and plenty of sun, you should be fine. And I would limit my choice to the Frost peach or Avalon Pride. These are varieties bred to do well in our cool summer climate and disease encouraging weather. Both will ripen with cooler temps and are resistant to leaf curl. Haven't tried the Avalon personally but Frost produces a delicious fruit.

My frost produced delicious fruit for 2 years. Then it succumbed to something that turned all the leaves and stems black and it died within a season. My area is WET. 800' elevation, near the Oregon border, above Vernonia.

I've had good luck with Frost, and it sounds like I'm in a similar situation although you might be at a higher elevation. We're in the foothills between Orting and South Prairie. I've been growing two Frost trees for several years here (maybe 12 years). The trees suffer most springs from a fungus or something that causes the leaves to curl, but they get past that. And they took a real beating with the freezing rain a year ago. But generally I get a heavy crop of peaches every other year.