Well, I'll take a crack at this one for you. (BTW, welcome to OSO.) I think you'll pretty quickly find that a Rinker just isn't a high performance boat. With a 496 in it, I doubt you'll get more than low 60's (true speed) out of it.
The big difference between a production boat with a high performance motor in it and a true high performance boat will be the hull design and construction. Lots of production manufacturers have built "performance" boats over the years. Sea Ray had the Pachange series. Celebrity had their Firestar series and I could go on and on. Most of them simply beat themselves to pieces.
If you really want to go fast, you really want to buy something built to go fast. You mentioned some decent high performance manufacturers, but even within them, there are good and bad models. And even in the good models, if the previous owner has abused it, you're in for a real dissapointment.
Can you find something in your price range? I'd say yes, but it's going to take some time and effort. I'd suggest finding somebody in your area who knows their stuff, and have them help you.