You don't want poly rope. It UV degrades, doesn't hold knots well,
and is not overly strong.
You don't want Nylon rope, either, as it's too stretchy.
Great for anchor lines for boats....lousy for pulling up tower
Double braided dacron works well. Very strong, low stretch.
While 3/8 is strong enough to hold rohn 45G with a safety factor,
it's a bit small to work with. I recommend using 1/2" minimum,
and in fact had 5/8" here, for ease of handling.
Haven't seen the rope from Home Depot, but will take a look at
Jim Jarvis, n2ea