Re: West to East - Trans-Pacific to Japan
Is your entire budget 25k or is it 25k to purchase and x amount to refit? I think most any boat in the size you are looking for will either have been used weekends and is not ready for offshore or will have been offshore and be in need of a refit.
I mean things like rigging, sails, and through hulls possibly. Then there are the additions like Epirb and liferaft, and self steering. None come cheap.
Like Marty I think many boats can do the trip, although some better than others. By that I mean you should look for things like a bridgedeck so any water in the cockpit doesn't end up below, bulkheads that are glassed in as opposed to screwed into a liner. Both these items would eliminate Catalina. Not that a Catalina couldn't do it, but it would take more work to get one ready, some structural.
As far as keel/rudder design the second Yamaha you linked to would be a better choice than the first more extreme design.
I think most figure about 20% of the purchase price more or less is expected to upgrade an older boat. If you want to head offshore I would think 30 to 50% for additions and refit costs. This assumes you are doing much yourself. If you have to pay a yard prices go up quickly.
It really comes down to what you find in your search, how expensive it is, and its condition.
Living aboard in Victoria Harbour