Do you want a turn key, water ready boat?
I'd suggest you dig in and start going to see LOTS of boats. Make and model wouldnt be as important to me as actual layout and condition, esp the layout in a turn key boat.
You have asked the boat equivalent of Ford v Chevy. LOTS of opinions wont reflect your actual needs, wants and uses of the boat.
A 16ft boat w a 25hp OB isnt going to be the same boat as a 17ftr w a 90hp.
You might find a mint condition early 90s 16ft Lund w a 50hp OB but when you go look, its not laid out the way you'd like. In a project boat thats not that big a deal, but turn key it could be.
Turn key at the price you want to spend is, IMO nearing the danger zone for boats. We've seen several spit shine dirty 'rehabs' sell for about $5K and they were cosmetic cover ups not really resto/rehabs. Not that decent $5K boats arent out there, they probably are, we just dont see any of 'em.
By seeing LOTS of boats from several makers and multiple sellers, you'll get a better sense of what, where and how to look at a used boat.
If you need to be under $6K, you'd better be ready to go see quick and be prepared to make an offer fast. This time of year, sales are starting to pick up as boating/fishing season gets close. You may not even have much time left for bargaining, there may be a good bit of competition from other buyers for most boats, esp turn key.
Good luck, as you find possible boats, you can post them here, and definitely report back what you decide to buy and drag home. Pix from the road are appreciated...
Welcome to iboats
Good luck