My opinion - you will probably regret it, rigged as is. At the very least, insist on a sea trial before purchasing.
Anything less than a 70/75HP outboard on a 19 is insufficient. They need to be powered exactly like a 22.
First hand knowledge here...I had the first C-Dory 19 Angler, and it was suggested I go with the Yamaha F60. Big mistake - it was an absolute dog, even when loaded lightly. The F60 was quickly yanked and replaced with an F80, and the change was huge.
Fortunately, in my case, I was working closely with C-Dory and the dealer to figure out the kinks in the newly released 19. As such, I was able to upgrade to the F80 for very little money - basically, the difference in what I paid for the F60, and dealer cost on the F80.
If the package were cheap enough to make a repower an option, it might be worth looking into. The Yamaha 60 should sell for a decent price, or a Yamaha dealer might give you a reasonable trade-in on it if you upgraded. But at $20K, I'm not sure that the numbers would come out on your side...