Need some advice/help

Ive got a caravan hire site ive built in wordpress. (is a theme)
What i want to do is add a caravans for sale section but the theme itself doesnt support that. What would be the best way to go about it?
Im thinking that it would be better for me to add them manually and send new additions as a newsletter whilst setting up a posts page that just has them on but i was wondering if there would be a better way.
I need it as simple as possible. This is my site www.flamingoland-caravan-hire.co.uk so does anyone have an idea how best it would be to go about it?