aftermarket parts designed for specifically for this bike are pretty rare.
If you are lookinf for saddle bags and trunks, your best bet is to search for universal fit items. Aside from that, your only option is the factory Suzuki stuff which costs way too much.
Sites that I check:
www.bikebandit.com
www.jcwhitney.com
www.ronayers.com
www.newenough.com
www.ebay.com