I agree with Blue Heron, I think your chances of finding the ideal boat for your purposes will be greatly enhanced if you don't limit your search to boats from just one country.
If your concern is quality as opposed to principle, there are and have been extremely good boats made in Asia: Grand Banks in Kowloon (wood) and Singapore (fiberglass), Nordhavn (PRC), Island Gypsy (Hong Kong/PRC), deFevers, Flemings, Victory Tug, the list is awfully long. Some of the Taiwan makes need careful scrutiny as their quality can be very inconsistent.
Made in the US is not automatically an indication of superior or even good quality, General Motors automotive products being one of the best examples of this over the years. Were we in the market for a diesel cruiser today I cannot think of any US-made brand that would interest us or meet our requirements other than a lobsterboat-type.