Loads of sound advice available, most of it contradictory. But thats how experience is gained, if you know three ways to solve a problem you have a fair chance.
Your first choice is Cat or Mono. Don't start a debate, just go and see both and choose. Older guys and ladies prefer bigger cats but they cost more.
Don't be afraid of older boats, just get a proper survey
done so you know what will need repairing now, and in the next couple of years then check your budget
You'll also need some idea on places to visit to get an ocean voyager or coast hopper. Three day forecasts are fairly reliable but that only gets you three or four hundred miles which will limit where you can go. And allow for a crewman or she. You never know!!