At the stage you seem to be in your boating I suggest forgetting about boat brands and models for now and define as thoroughly and realistically as possible what you want to do with a boat. Think of it like buying a computer. First figure out what software and applications you want to use, then find a computer that will do a good job of running them.
So where are you going to boat? How many people on board? Kids, old folks? Will one head or two suit your needs? Do you mind a lot of levels or is climbing up and down steps all day not something you or someone with you wants or can do? Any pets? Are you mostly going to go to marinas and docks? Do you anticipate anchoring out a lot? Will you need a source of power independent of the shore? Do you want to cook with gas or elctricity? And on and on and on.
The list you compile will broadly define the boat you need. At that point you can start looking for makes and models that meet that need.
Your budget will obviously determine what you can get. And don't forget to account for annual ownership costs in determining what you can afford. Boats don't stop costing money once you buy it. Annual ownership costs include moorage, electricity, maybe water, insurance, fuel, service and maintenance, repairs, upgrades--- basically every cost associated with owning and operating the boat except for finance payments if you finance the boat.
And while some argue this figure, a very average figure to use in accounting for the ownership costs in your budget planning is ten percent of the purchase price of the boat per year for as many years as you own the boat. Some years will be less, some will be more. The figure will vary with the condition of the boat. But unless you are buying a new or very new boat, that ten percent of the purchase price figure is a safe one to use for your initial budget calculations.
Engine hours are not nearly as relevant to an engine's condition as the way they were operated and maintained by the previous owner(s). All else being equal, I would rather buy a boat with 7,000 hours on engines I know were properly operated and maintained than a boat with 2,000 hours on engines that were, or were likely, abused or poorly maintained.
As to age or an era, I have seen boats from the 1970s that are in better shape physically and mechanically than boats from the 1990s. A lot of it has to do with the initial quality of the boat. But even more of it has to do with how the boat was treated, used, and maintained.
On our recently completed cruise in the Gulf Islands in BC we shared docks with two boats that beat any other boats I've ever seen in terms of condition. (photos below) One was a 1971 (IIRC) American Marine 49' Alaskan (American Marine also created the Grand Banks line of boats). Alaskans were all made of wood in the company's Kowloon yard but the exterior finish on this one made it look like a new fiberglass boat. And the interior was simply spectacular.
The other one was a 1975 Grand Banks 42. (GBs started in wood in Kowloon in 1966 and were switched to fiberglass in 1973 in AM's then-new Singapore yard.) It is probably the best Grand Banks I have ever seen in terms of condition, including the nice, late-model shiny ones in the big Grand Banks charter fleet in our marina.
So the year does not necessarily have any bearing on the condition of a boat.