Catalina would not be considered a bluewater boat... though I always cringe at that term. It is considered a coastal cruiser. In my definition of a coastal cruiser, it is a boat that is typically very roomy and comfortable down below, with the emphasis on liveability versus crossing oceans. A good coastal cruiser will be able to take several days offshore in good to moderate conditions without endangering the crew.
A blue water boat, in my opinion, is a very strong, very sturdy boat set up for ocean corssings. They are typically tight down below and tight in the cockpit. Livability is second to safety for long ocean crossings (2 weeks or beter at sea). They will take longer beatings from seas and storms and given two captains of equal skill, are more likely to survive the worst nature has to throw at it.
Now... which one do you need? If you are going to cross the Pacific (which Catalinas have done, incidentally), if you are going to Australia, around the horn, the red sea, across the Atalantic on your way to the islands... then by all means: go buy a good, solid "blue water" boat. However, if you are priamrily going to be living on your boat and exploring this hemisphere, not only do you not need a blue water boat, it would be as bad of a decision as taking a Catalina across the Pacific.
If you will also notice, I said given two equal captains. The captain will play the key role in how you survive... not the boat. For some reason I fail to understand, people are always so focused on the best electronics and toughest boats as going to save their butts from their total lack of seamanship and knowledge of offshore passagemaking and storm survival. Bottom line is, with you knowledge, you probably cannot afford a solid blue water boat and it is the WRONG decision for you... as much as you would not buy a Lexus to haul cow **** around. Go buy a Ford. It is not built as well, but it serves a different purpose the Lexus "should" not fill and was not inteded for.
In the realm of coastal cruisers, there are better ones and better constructed ones, and there are worse ones down to flat junk. Boats are very expensive. Even a cheap coastal cruiser will cost you many, many tens of thousands. You can get cheaper ones... but if you do, you better bet there is a reason for it. Maintenance on a boat is high. Slippage and insurance is out of this world (especially in the seast).
I am not trying to scare you off. I hope you do buy a boat and a nice one. For all of its expenses and headaches, it is a very rewarding lifestyle. But it is not a cheap lifestyle. I think you will be best served with a good, solid coastal cruiser like a Jeauneau, Beneteau or Catalina and would be poorly served by a Valiant, Hylas, Hallberg-Rassy, or any other super bluewater vessel. You are also better served increasing your $$ upfront for a boat that will cost you less after you sign your name. I am concerned at the budeted amount you have alloted, you are going to get a lemon and will be spending more money just to keep it floating than you paid for it.
These are just my opinions. Others may differ. I hope that helps.