I have been toying with a similar project on my 18'. Looking at the the stringer drawings you should have what looks like a nice "void" you could utilize.
Attached is a drawing for a 1993 so it looks promising. Just use a strong lid as this area will likely see lots of traffic.
I teepee my boat and use a generic cover ($250) More than 5 years old and still in good shape. No puddles is the key.
It all comes down to how much value is your time worth and are you capable. Some people tarp like a 9 year old, they deserve what they get.
Shrink wrap isn't for me at this time...
I scored one local on CL this spring, that swingback had to go. I think it was 250 but needed hours of polishing but it looks great.
They pop up on CL every now and then. There's one fleabay.