For me then my list of must's is:
Must be able to take my toys, few sets of dive gear including compressor, mountain bike and surf boards. I'm not one of those anally neat storage people, and hate climbing under too much stuff to get what I want so will require a bit more space that many.
Must be able to make ocean passages with a few people in comfort.
Must have the space for a small party on deck.
To me that means it's primarily a cruiser. I doubt then I'd get away with anything under 40ft which on my budget won't be in the best condition, however I won't need to pay labour for any repairs, and don't shy from the work.
Maybe the best option is to keep saving for another year, but then where does that end. At the end of next year I will surely want a boat costing more that I have. I've been saving for this for almost 2 years now, and though originally had a target of £100k I've been getting into the comfort zone of not doing anything about it, just saving. Maybe it's time to take the leap?