When it comes to a long distance voyage, a lot more should go into preparation than simply using vacuum packed bags and pre-prepared food. That Catalina sounded pretty beat up. I always include a series of inspections by professionals which would include basic items like:
1. Standing Rigging
3. Blocks, hatches, any deck penetration.
4. Keel bolts, through hulls
9. Life Raft Certification Up To Date
10. Safety Equipment Check List in Compliance with Ocean Races such as Newport to Bermuda.
11. Sails examined by Sailmaker.
(To name a few). But you want a good twice over by someone who actually knows what they are doing might save your life.
As for the point of whether you should buy a new or used boat that is a matter of personal choice. The US has not adopted the EU boat rating standards yet but certain manufacturers like Island Packet have complied. So that might be a way to check. There are others on this site who can address this point in more detail but suffice it to say you that the seaworthiness of a boat for blue water purposes has been quantified. You can look that number up and find out if the boat has the right weight to length ratio to be safe in heavy seas. And frankly, that is the issue. The conditions described in that article were not particularly challenging. A boat in good condition with the right sail plan employed should comfortably handle 30 knots and 30 foot rolling waves.