Your biggest issue 'may' be getting that product to stick to the cladding plastic.
A bonding primer is often needed to get adhesion between cladding & finish coat.
So check that out carefully when you contact the supplier.
Line-X prices seem to vary dramatically across the country !
I've seen $400-$1200 for just the cladding.
No harm in calling your local Line-X guy to get a quote!
Jo