First I would check with the dealer where you bought your trailer from. Secondly I would check with any local outlets that specialize in hitch installations. If you feel comfortable installing yourself, surf the Internet.
I bought my dual-cam with my SOB trailer about 6 years ago. I negotiated a purchase at dealer's cost. With my Airstream's I have added installation of my dual-cam for no cost as part of my order.
'04 Classic 30' S.O.,'03 GMC Savana 2500,'14 Honda CTX 700