I redid mine. Bought everything off of the web. Most made by C.E. Smith. Got some 2x6s from Lowes. Very simple with u bolts big enough to fit over the frame and heavy duty bolts. Currently, I am looking for some Cypress 2x6s to replace my bunk boards. I do not like the treated pine. I can just tell it is not going to hold up. Very little weight on the front bunks, but it won't last.
Sounds same as mine-5' bunks w/2 brackets/side. Hartwell is a big lake that handles holiday weekends well. Lanier is a big lake that is horrible on holiday weekends, but nice otherwise. Lake Russell is our favorite. No houses whatsoever and almost no boats-very pristine.
I usually don't boat in the summer time, too hot and too many people make it crowded. I wait until Oct to go out not this year boat needs all new cushions. If you find Cypress let me know, untreated southern pine is good for melting marshmellows....