Here are the 2007 fast facts (right click, save as):
http://www.fourwinns.com/upload/Documen ... s_2007.pdfThe 5.0GL actually had 220 HP in 2007. According to fast facts, top speed is 45-48 MPH. I think it would be plenty quick for what you want to do with it. What kind of lake do you want to use it on? Would be perfect for an inland lake but I would not recommend it on big lakes that get really rough/choppy.
When looking at a boat, make sure it is in good condition and the maintenance schedule was followed and is up to date. Interior and drivetrain repairs add up really fast.
With that said, I have a preference for fuel injected engines (Gi, GXi, MPI, etc) but realize they are somewhat rare. But if you can find one, I would recommend it.