The Valley Forge Chapter of the American Rhododendron Society has been known to carry them in their annual plant sale on the first weekend in May. Prior sales and meetings have been held at the Jenkins Arboretum, south of Valley Forge Park: 631 Berwyn Baptist Road, Devon, PA 19333. Sale hours on Sat 9am-3pm; Sun 11am-3pm. Pre-sale Party on Friday 6-9pm. Plants are sold at the pre-sale party too but that costs $40, while the regular plant sale has free admission. Plants sold include azaleas, rhododendrons, and, of course, vireyas, which are tropical; camellias; shrubs, Japanenese Maples, blueberries and other trees; perennials/ferns/etc. Bring cash, checks or plastic. The following weekend, they sell locally grown azaleas and rhodies.
See http://www.valleyforgears.org/

Thanks.

Do you have a greenhouse?

Yes.